This puts the LLM providers in a great position of:
<prompt text> -> [PROVIDER] -> <lots of output text> -> [PROVIDER] -> <prompt text, mangled>
They're getting paid to encode some inane prompt into paragraphs of text, and then they're getting paid again to summarize that back into something with even less value than the original prompt. And they're making money hand over fist because people are happier to play that game rather than just pushing back on the jerks sending them pages of generated garbage in the first place.
I would agree with you, except right now the walls of text come from people using the free or very cheap versions of ChatGPT, et al. So there's not even anyone making money off of it.