1999 and 2002 correspond roughly to telecom and dotcom bubbles popping. So open source operating systems were also pulled up into these positions through a lot of work and by the early 2000s it was kind of obvious this was the way forward.
2008 financial crisis really knocked the high end (RISC/UNIX/Itanium) and started the long migration to renting vs owning. In hindsight it's remarkable how much money used to just be there in the economy of all this. But I guess it still is, considering how expensive public cloud is.
It's not like there's less servers being sold, they're just bespoke designs from companies like the big Taiwanese ODMs that go straight into hyperscaler facilities, and we don't get to see public marketing websites and product info about them. The open compute platform stuff that's been publicly shown is like the tip of an iceberg.
I find it a real shame it's not easier to get OCP hardware for our homelabs. Would be so much easier to operate, upgrade, and so on. And where would you even get decommissioned OCP gear?
This is just criminal. Reusing is much better than recycling.