@pglpm @digdilem
If by Ubuntu you refer to brand, trademark Ubuntu then absolutely yes.

@spacesweedkid27
Debian, is definitly good to substitute Ubuntu. Although as mentioned flatpak/appimg is a must. Example: waterfox installed from outside repo made for Debian bookworm complains about dependecy issue, Ubuntu drivers just works Debian had a discussion about non free drivers in standard repo. Repo is named non-free-firmware, and still broadcom is not in standard repo you need to add repo. In the end you'll have low maintenance distro, setup is more engaging for some hardware.

@lemminer @fruitywelsh
Appimage is OK but no auto update makes it download and forget type of deal - definitely not for every app
Flatpak - best for me but permissions on some apps make it unusable e.g. gpodder - command for player as flatpak is unable to access MPV installed from repo flatpak etc. - sandboxing (couldn't fix it with flatseal mpv --profile=... not working)
- snaps people love to hate them... no love from me :-)
Repo if it works, is available - the best option

@Dirk @Fungus
Arch + aur is a little bit too much in my opinion. Old PC = old slow hardware. Some of aur pacages are basicly compile instructions. Also you won't benefit as much from rolling release.
For GUI stay away from GNOME as it is resource hungry. KDE claimes to be a lot better but honestly it is still a very polished flashy expirence out of the box.
Learn using KDE, atempt to replicate using window manager like AwesomeWM.
You will "waste" resource only for what is a mass have for You.

@Lazylazycat @Anarch157a
Dual booting is an option
If you go with Ubuntu (best starting distro in my opinion) you will be able to install Linux alongside windows but there is a need for repartioning the drive.

Tutorial:
https://itsfoss.com/install-ubuntu-1404-dual-boot-mode-windows-8-81-uefi/

@cloudwanderer rofi as a window switcher, in KDE default runner has window switching.

@CalcProgrammer1 @KindaABigDyl
How does the battery stack against galaxy? My biggest concern is getting Linux phone that will act like it has 3-4 year old battery that is clearly dying.

@theodore @bookworm
Lf list files
https://github.com/gokcehan/lf

I switched from ranger for better performance. Ranger was a bit laggy upon entering large folders. Ranger is definitely straightforward when it comes to previews.