Even if there are people, today, that do publish valuable stuff on the internet only because (or thanks to) the expected traffic (either own ads or selling ad space), I claim that without that traffic, there will be others who will be publishing valuable stuff, and the traffic incentivized garbage more than the valuable stuff.
Finally, if that's not the case, then in order for the LLM to be useful, it needs valuable training data. So this problem solves itself - competitive LLM company will need to pay for the data directly, and for me, that model incentivizes valuable stuff more than garbage.
In the meantime, I think people should focus on attribution, and algorithms to find related work (which may suitably substitute for the former). This will allow us to fund creators and publishers for AI output, maybe by forcing the AI companies, or naturally through patronage (see AI output you like, find who owns the training data that contributed to it, donate to them). Moreover, it will help people discover more interesting things and creators.