alt Hacker NewsNo, they wouldn't.
We've been doing Bayesian content (aka spam) filtering for over 20 years, based in no small part on Paul Graham's essay "A plan for spam". According to HP [1], a home computer at the time had a single 1.5Ghz core and 256Mb of RAM.
Using LLMs would achieve essentially the same while requiring a couple orders of magnitude more resources.
[1] https://www.hp.com/us-en/shop/tech-takes/specifications-pers...
Would those filters be keyword-based only? One benefit of an LLM-based filter I can imagine is that it has a much better understanding of the meaning of text.