[m10k]

Let's be honest, "you can change what you want" should really be "you will have to change certain things". Which is fine for developery people and people with a lot of time and patience on their hands. But for the overwhelming majority, even fiddling with the contents of /etc or $HOME/.whatever is too much of a hurdle. People don't choose Windows or Mac despite not being able to change things, they choose it so they don't have to change things.

And let's not forget that, eventually, "you can change what you want" becomes "you have to change what you want" because the developers of your distro / desktop environment / window manager / UI toolkit decide to change the default behavior (if they don't change the entire thing).

[vanviegen]

I don't understand? What are these things you have to change?

Your second paragraph mentions changing defaults. Of course software evolves over the decades. You may not like every change, but evolving along is always an option, of you don't want to tinker. Also, most UI config is stored in dotfiles. Upgrading doesn't apply the new defaults to an existing account.

[humanistbot]

Ubuntu is terrible for this. Every new version comes with a UI redesign, and the 20.04 switch was particularly painful.