The thing is you can’t regulate word of mouth. It just pushes the money underground, where it can’t be taxed. People will still be paid to promote things, they’ll just pass it off as their own opinion, and it’ll be more insidious. Like it or not, at least advertising now often is clearly advertising. Not always, but often.
Or just let this LLM mania run to its conclusion, and we'll end up with two webs, one for profit for AI by AI and one where people put their shit for themselves (and don't really care what others think about it, or if they remix it, or ...).
There are already a lot of initiatives following this logic (like the small web movement, the indieweb, gemini/gopher protocols...), but the problem here is that people are using the web, not those projects. Even the fediverse is growing slowly, while it's using the web.