How about exchange of services?
I do your garden, you fix my roof, I take care of or yeach your child, you cook me a decent meal, etc.
We all have skills, likes, dislikes, knowledge we can share for free and basic needs. The price is what it is worth to you.
If it comes to the providers the example is badly chosen. You have to agree if you do not agree you have no internet. Once the contract is signed there is no service. They can easily shut you down or slow your connection down and make you pay the full price without any compensation or guarantee.
Happy day 💕
Barter, in my opinion, is not practical at scale and can only work in very high trust situations. Internet is an example of a government-created monopoly. Their regulations prevent competing service providers in the same area.
Should it all be practical on scale? For sure it will be in some way since people travel.