There are many other more practical sources of random number generation, including ones that are non-deterministic due to quantum effects. SGI did it for fun, and obviously someone at Cloudflare was a fan.
I'm also confused by the second statement. You believe that more people have seen lava lamps in video games and similar than ones in person, or photos/videos of real ones? This seems unlikely to me.
Yes as a matter of fact I do believe people see lava lamps in digital media more often than in real life. I am one example of such a person. Lava lamps are an American thing largely, so if you want to see them you need to bring one from America or go to America to see it. What is the alternative? Lava lamp in the media, where you can look at it many times, but it is always a rerun.
The lava lamps are completely impractical. You'd get randomness of equal quality for orders of magnitude less energy by turning the lamps off and putting a lens cap over the webcam they use to record them.
Note also most people have never seen a real lava lamp, only digital reproductions, like the one in Day of the Tentacle. Not the same thing.