Personally, I'm more-sure that Cloudflare will be around in 25 years than I am that Facebook will be around in 25 years. Their customers are real-valuable customers paying for a real-valuable service, and that's not going away anytime soon. Meanwhile, their serverless stuff is very cool and unique. I think their durable objects are going to go mainstream someday. They work on hard/interesting/real technology, that's gotta be worth something.
I predict that one day, we'll see a C somewhere in "FAANGM".