The point of using an LLM is to find the thing that matches your preferences the best. As soon as the amount of money the LLM company makes plays into what's shown, the LLM is no longer aligned with the user, and no longer a good tool.
But it's not only money's influence on the company, it's also money's influence on the /data/ underlying the platform that undermines the tool.
Once financial incentives are in place, what will be the AI equivalent of review bombing, SEO, linkjacking, google bombing, and similar bad behaviors that undermine the quality of the source data?
No implementation will work for very long when the incentives behind it are misaligned.
The most important part of the architecture is that the user controls it for the user's best interests.