Lotta speculation about it's value but seems cloudflare does legitimately use this source.

https://blog.cloudflare.com/lavarand-in-production-the-nitty...

They even mention it's origins in Lavarand (and LavaRand) the former which has an actual patent: https://patents.google.com/patent/US5732138A/en

Yes there's a bit of theater here, and they admit to using the sensor noise as well, it's also not their only source of physical entropy. While you could do just as much with less interesting sources the wall of lava lamps is a perfectly cromulent source of randomness, also is kinda fun.