In the US, a lot of Lowes Hardware Stores use Linux on their employee computers. Most movie theater projectors are running CentOS, and most movies that come in on hard drives are formatted to Ext2.
I opened my first Gmail account during the private beta (2004). It's not my daily driver account, but I still use it for government stuff like taxes and healthcare. It kinda blows my mind that it's 20 years old.
Immutable and Declarative OS design is simply an option. I think it's a damn good one, but right now, it's not for me. That could easily change in the near future.
The idea excites me. A potential hardened OS that user-friendly could be a great option for Business and Academic computing.
See, here's the thing about open source, you have the source. You can always compile a discontinued program. You can even update the code if you want. No one can say "You can't run it anymore". I can grab Linux Kernel 0.01 and still compile it. No one will stop me. No one!
Gimp doesn't suck as an image editor, it just sucks as a Photoshop clone, which it was never meant to be. It's an amazing image editor.