Delegation of stake was not originally convenient, but I don't think it was ever fully impossible. In the absolutely earliest days of the chain, it still needed cli wallets and arcane and obscure steps that made all the stuff hard to do, and many things weren't obvious to users. Not sure if it was ever simply not possible.
But no, that wouldn't stop it. You can still make deals to loan sp, via contracts and trust, or just load your own accounts up and run bid bots on them directly. It might mitigate some by complexity, but it wont stop it. Just make it look different.
It's impossible to stop users from using the accounts and money to do any of the things, it is only possible to change how easy or well known doing such things is (like not making bot tracker pages for example) but that all depends on the consumers too.
And right now, about a third of consumers and a large number of stake holders support a bid bot industry. Cool for other users? Debatable. Going away? No. Deal with it? Deal we must.
Adapt, improvise and overcome. Also use the enemies weapons against them. Don't like trending? Bot better shit up there. This is the tool, and this is the battleground. Pick up arms, or be shot down.
Such is life on the chain.
Although I don't like them, you are fully right about everything you said.
Thanks for all your replies and the good conversation!