There are clear benefits, such as participation in the political process (up to and including becoming a political figure) access to markets, welfare, healthcare (in most 1st world countries), protection when abroad, etc. That this is balanced by responsibilities does not diminish the benefits.
We can debate if these are actually benefits. It is true people for example receive welfare but it is also true that people are put into a position of poverty in the first place by the same system which offers welfare to alleviate it. Poverty is a result of the laws, the culture, the society people live in. Welfare is a band aid solution to a deeper problem in my opinion.
Participation in markets doesn't specifically require a nation state. Just look at the blockchain and you can see we don't need a government for that. That is why I never included that. I included the passport because the passport is something only a state can currently give. Markets exist regardless because humans will always form them when the technology exists (which it does).
Participation in the political process is a responsibility not a benefit. What do you get as a reward for being a voter? You must give up time (quite a bit to research how to vote and then at least a day to go vote). I don't see any benefit to those who sacrifice themselves to serve politically. It looks to me like it's a lifestyle filled with immeasurably high costs.
Healthcare I agree with you is an actual benefit but again it's not really a benefit which requires a government to give. I would say most of the benefits you mention are benefits to certain people in certain economic circumstances but once these people become multimillionaires (their circumstances change) then these benefits become only responsibilities.
Protection while abroad, if you mean having good passport and having access to an embassy then maybe I can see that. But I don't think there is as much protection abroad as people seem to think. In fact, if you are abroad you can be spied on legally, by your own government and by foreign governments. Of course if a person is stateless then I can imagine the gloves come off completely so I question what happens to people who renounce their citizenship. What would stop their former government from declaring them foreign and being completely unleashed?
If you're poor, if you're homeless, then I agree to live under a state government which offers healthcare is a blessing. If you're doing well, or if you're rich, it's not so much of a blessing anymore. It means more responsibility for you to pay higher taxes to support others. So ultimately the more successful you become the more responsibilities you inherit in the system.
I think this arises from the over-abstraction of what it is. We think for example that we sell our time to employers as work in exchange for money. That abstraction is useful, but really we actually do work, minute to minute we are doing some task or other. Similarly with citizenship it's useful to a degree to think of it as a thing of exchange but really there can be no exchange with the state, monarch or god. We are in a relationship but it is not with a peer and exchange only makes sense in peer to peer relationships (I would be happy to expand on this if you want).
I already agree with you on that. The idea of selling citizenship never made sense to me for similar reasons.
One other thought - though citizenship is often discussed in terms of trying to get it, there is a certain strangeness to a person being claimed by the state by the mechanism of citizenship. Surely this harkens back to being a "subject" of a monarch, which precedes all modern democracies in lineage. The claim of the anarchists that citizenship is a tyranny makes more sense in this light, but the practical fact remains.
Should nations get rid of birth right citizenship? As another person mentioned, it's not their fault that they were born into a certain nation. Maybe if we get rid of this idea of birth right citizen or if we give people some way to at age 21 renounce rather than enlist then this would provide more options? I don't really know but I don't see much benefit to renouncing because I don't see that stateless people are living far better lives than people living in states. So from a pure cost vs benefit analysis I would think being stateless costs more which is why people who are billionaires aren't trying to be stateless.
While poverty is a condition which the state contributes toward, by upholding social orders that keep socioeconomic losers as losers, that does not mean that welfare is not a benefit. Welfare is an attempt at balance without massive social change.
I've been listening to a lot of Jonathan Haidt and Jordan Peterson and I think they both have elaborated some important insights. (btw it would be unfair of you to dismiss me based on any prejudice you may have regarding these men, JP especially is polarising I know). One key insight is that of conservatism, that changing society radically is potentially dangerous because we can't predict the results. Thus we have the gravitation towards norms, and the enforcement of these norms, and a resistance to changing them. Haidt's contribution here is that openness to new experiences and other personality traits largely predict political orientation, and so those willing to make changes often make their judgements based on emotion and partial .
5 years ago I would have said that because poverty is a necessary effect of the systems we have in place that we need to remove or radically change them. Stephen Pinker recently came out with a book Enlightenment Now in which he makes the case that things are actually getting better over all. That goes for poverty too. Now I haven't actually read the book, I'm hoping to get it as an audio book, but I've seen data that supports that before, perhaps you have come across some similar information.
It's true that the state maintains poverty even in fundamental ways, such as defining private property. It's not clear that government programmes such as welfare work to alleviate it (there's evidence it makes it worse in some cases) though the case of my own country (Ireland) it's more surely indicated that it does work, at least for most. However as we've seen historically removing private property has not worked in practice. There are some middle ways which are interesting, collective ownership, co-ops, etc. but I have observed that these things are practically limited.
The other claims of benefit I think are easier to see and I don't think you can dismiss them by making the argument that the benefit is relative to income / wealth / class. For example, the lower class person who gets a lot of utility from universal healthcare doesn't get a lot from access to markets, as they work in a factory. The middle class business owner who has private medical insurance gets access to markets, ability to incorporate their company, business tax breaks, etc.
Protection abroad is real. I doesn't mean Navy Seals are going to jump out of the sky to save you from getting mugged, but your country will go as far as trying to bargain with terrorists for your life in the extreme case, or just embassy access which can go a long way, depending on your country.
The other point you make is that the state is not required for much of this. I agree, but that's quite hypothetical. We find ourselves now in a world of states, so it's neither here nor there whether these things can be provided / required without states.