I’m just taking a guess here but is the .deb you installed a program you have to run to do the setup? My one printer I had to run a program to start scanning every time.
Ubuntu in my experience works best out of the box and has the best support reference online. Ubuntu works out of the box save for the webcam where Debian doesn’t even boot on my MacBook.
Rhythmbox is great and works well for editing tags for my 15,000 track library. I went to Lollypop for a while trying to get some more features but I ended up back at Rhythmbox.
The differences between distros are the things you mentioned. They all use the Linux kernel, so the differences are in the DE, installer, theme, default packages, and package manager. These changes come about from design choices: rolling vs versioned releases, stability goals, FOSS vs proprietary packages/repositories, things like systemd vs alternatives, and overall goals/use cases (lightweight, server, etc).
A distro can be as little as a theme change. The famous Hannah Montana Linux is KUbuntu with a custom theme, icon pack, and Hannah Montana as the background.