That's a bad move of Google, this has no reason at all!
Chroot/docker will use a more practical way to run Linux, as Android is just a Linux distro, why bother with running a whole another kernel!

You can say: "I use Arch, Fedora, Windows, MacOS, Gentoo, LFS, Debian, PopOS, and more, btw."

Well, not exactly. Any distro COULD be used for development and excel at it, but there are a few intresting options out there. I personally use Fedora with KDE, but if you want to take it to a more advanced level, use arch or nixos. If you want to make your OS, use gentoo or linux from scratch, but very niche and not recommended.

A FOSS alternative to wannacry?

Jetbrains? Use vim :) Just kidding. As for Excel, you can use LibreOffice calc, or OnlyOffice. Or any office... or Excel web. As for onedrive, i remeber linking my gdrive to my gnome files, but i personally don't need it that much, i use git lab/hub. btw as for linking to phone, I recommend using KDE Connect.

nixos

remove backgrounds? i think you could find a krita plugin for it, or just use an online website / huggingface space.

If it's unix, sudo rm -rf /* the system without mercy! If it's windows, nah, it will win.

GitLab, because it's FOSS.

Interesting... but well.. Android isn't rooted, so will it use chroot or something like that? Or it will use a whole another kernel, complete VM?