I'm running a somewhat similar website (https://Docalysis.com/) where users chat with files, and it's clear there's a lot of value being added, so people are willing to pay.
What's less clear is how this all plays out when there's more competition, but it's not like we'll all go out of business. It'll just be a bit harder, or you'll have to do things to differentiate. I'm planning on differentiating more, just using the current product as a starting point. Yasser probably is thinking along similar lines.
Good on him for making this much cash. Sure, right time and right place but you still need to be able to execute.
We have been adding LLMs to our products in a little test for clients who want to try it. It's not a fad as far as I got the feedback; it saves people are lot of work and allows juniors at our clients to do far more. I believe it retains clients and will pick up new ones. So when the fads with LLMs die out, the products that have marketshare and add them (b2b anyway), will benefit a lot.
Many of these companies are throwing money at these kinds of early-mover products, but are likely to stop doing that as people start to get wise to just how useful all this actually is, and for what.
[EDIT] This is not to claim that AI-based products won't find actually beneficial uses in various companies, but a lot of these trivial get-to-market-fast companies are raking in quite a bit of money from hype-chasers, and that money isn't going to stick around long-term.