- Apps running with your user privileges inside a sandbox by default. I'm very uneasy knowing that a PDF reader has unrestricted access to my entire $HOME, and so every code run by "pip install", "npm install", etc.

- A different concept of package management, that you can freely install any version of applications and libraries, coexisting together, without the rigidness of Debian, Ubuntu and the likes, and the fast moving-target of Arch Linux. This would partially make solutions like Docker unnecessary, because the packaging pinned versions of dependencies would not be a problem anymore.

- A damn system-wide desktop mouse wheel speed configuration, so people would not resort to hacks like imwheel...

Advertise that it runs on hardware designed for it, not on every Windows-certified laptops. Wrong advertisement resulted in a myth that Linux is not a stable OS and that it always has problems with drivers or suspend. If your machine is designed for Linux, it will run flawlessly.

I'd prioritize the multimedia stacks, have a rolling age limit for old hardware support and phase out plans. But I'm welcome to more experienced linuxers telling me why this is a bad idea.

Linux needs better user ergonomics. Even now it's incredibly frustrating to do things that are trivial with a Mac or PC. Don't even get me started about xrandr (arandr).

Write it in Rust obviously.

Get rid of the OOM Killer.

I'd make it a message passing micro kernel.

mail a free ISO or live disk to as many people as possible, make the AOL campaign pale in comparison.

remove all the legacy code and only support modern systems unless you build your own kernel. Enough with legacy support already