It would since the app is a modified version of discord.
It did do it on old versions now it doesn't.
git not installed in ubuntu based distro was the shock for me.
Opensource is a more used term compared to foss. So popularity wise it was chosen is my guess.
Roblox is working on it there is unofficial way using grapejuice coming soon.
Flatpak and snap don't use system theme unless you tell it.
https://itsfoss.com/flatpak-app-apply-theme/
https://www.omgubuntu.co.uk/2020/06/change-snap-app-theme/amp
Have you tried distrobox ? That would sound more reasonable.
That is why forks like librewolf exist.
It looks like it runs in wine. https://www.reddit.com/r/scrivener/comments/102pvtk/scrivener_on_linux_abandoned/
Mint is easiest for old windows users.
You can change the kernel if you want through update manager.Linux mint doesnt always follow with ubuntu.
Endeavouros would be recommended if you like arch , if you want an rolling relase you could try Opensuse Tumbleweed, or fairly updated but stable then Fedora.
Mint has a more noob friendly approach with almost everything having a ui and it is Ubuntu under the hood so there wouldn't be extra to learn after switching. Popularity wise mint is one of the best stable distros with Ubuntu as its base with community support as well so if you have doubts you can most probably find the answer just by searching