Debian is more bare bones then Ubuntu, that’s why. Ubuntu comes with a lot of packages already installed by default. In Debian you have to install a lot of that stuff manually. You might also have to edit some configs for example. It’s not that hard, but maybe a little too much for a beginner.

I upgraded Debian to 12 last night, which required manually updating the source.list for the apt repos for example. It’s been a while but I’m pretty sure Ubuntu gives you a UI for upgrades? Upgrading Debian was simple for a techie who’s played around in Linux already, but it could be more intimidating for a newbie.

Depends on your distro and what’s available in the repo. With default repos you’re more trusting the distro developer to vet packages.

I trust debian for that. It’s been a while since I used Ubuntu so I don’t remember how their repos are set up but the debian team is notoriously conservative with their repos.