To filter bullshit it would first have to understand bullshit, and it doesn't. That's why an LLM will tell you the solution to a problem that doesn't work, and argue with you when you correct it.
For me, it's a resource wasting text generator. I'll not lie, I don't use OpenAI, Mistral or Anthropic's models, even for coding. I prefer to read my API docs and cry once.
I used Gemini, five or six times in total. Twice I asked a couple of very specific things, and it unearthed them. Since they were not products, but information, that was helpful. Twice, it has given wrong information. When I "told" it, there was another way, it said "of course there are two ways", etc. Tasteless and time wasting.
I don't like using an LLM all day long, or offload my thinking to them. It's the ultimate self-poisoning incident.
And as you say, these algorithms can't know right/wrong/logical/bullshit, etc. They just spew out text.
With LLMs, everything is given the same importance so you have no idea if the data came from a reputable source or an obvious SEO junk website.