I recently had an experience with a family member's Ubuntu LTS machine where it was stuck on an old release, /etc/apt/sources.list needed to be edited because of Ubuntu's obnoxious habit of breaking old repositories, and then I needed to debug apt issues to get do-release-upgrade to actually work.

The Macs and iPads have their own problems, but nothing like that.

But how old exactly?

https://ubuntu.com/about/release-cycle

The 16.04 is still supported and it was released in 2016! So it must have been an even older system, right?

Eh. You just install codex or Claude code and tell it to fix it for you.