To be fair the basic ASCII keyboard is also default in US/Britain. And most people assume that's all they get.

I have always used the "international" version of the US English keyboard on Linux.

And I can enter all common symbols pressing altgr or altgr-shift. I also use right Ctrl as a compose key fore more. I would be hard pressed remembering what combo to press, after years it's just muscle memory.

But how do you find out what layout and what compose key does what? Good luck. It's as documented as gesture and hidden menus on iOS and MacOS. sigh.