It may depend on what you mean exactly by desktop. If you want a full-blown desktop environment like Gnome or KDE, then you may be better off going with Ubuntu, since you already have some Debian experience anyway. Debian and Ubuntu are very similar, with Debian having a more conservative and Free Software focus, whereas Ubuntu is often treated as the default "desktop Linux" by vendors who want to make their proprietary software available to Linux consumers.

I'll answer from the perspective of someone who has a fairly custom and lightweight environment based on suckless tools like dwm and st. Despite the lack of complexity, I still run Steam and all the other software I need just fine.

My personal synopsis of the possibilities:

* Ubuntu is easy to install, and as I said above, whenever anyone is going to support a Linux distribution, they'll prioritize Ubuntu. However, I found Ubuntu hard to customize, and I don't like reinstalling every two years. Summary: Good for newbies and people who don't want to think about their Linux; people with a hacker spirit will want to move on after a while.

* Debian is actually okay on the desktop. I used it for a while. It's very similar to Ubuntu. Note that I can't vouch for gaming on debian, I used it in the days before Steam became very widespread. Maybe it will be fine, although maybe less easy than Ubuntu.

* I quite liked Arch Linux 12 years ago, but their developer culture changed in around 2013 or 2014 and I haven't enjoyed the trajectory of the distro since then. It no longer feels minimal and user-centric; I recently tried it again on a new desktop and found it hard to tolerate how opinionated it has become. I'll probably install Ubuntu on that box so I will have an environment more similar to our servers at $DAYJOB.

* Void Linux is a perfectly fine distribution. It reminds me of a cross between debian and how Arch Linux used to be in the old days. It was my daily driver for remote work during the peak of the covid years and I rarely had any problems. It runs Steam fine. I sometimes became frustrated with delayed releases of new package versions, and also needing to install development header packages when trying to compile software. One of the things I liked about Arch Linux was that it didn't make this separation, so it was very developer friendly.

* Gentoo is my current preferred distro. It can take a long time to learn how to get the most out of it (in fact, I still feel like there are things I should learn more about), but it's really very mature and customizable. I've been using it as my main driver for remote work for a couple of years and everything I need runs fine, including Steam.

Things to think about when weighing your options:

* Are you okay with systemd or do you need something else?

* Do you want to rebuild every now and then when a new version of the distro comes out, or do you want rolling release?

* Do you plan to compile a lot of stuff from source? If so, you may want a distro that doesn't separate out the development headers, and makes it easy to script custom packages for the package managers.

* Are you happy with a large generic desktop environment, or do you like to heavily customize your experience?

I wouldn't worry too much about whether a distro supports gaming, the important thing is that the distro has a philosophy and direction that you can get behind. Once you load Steam up, gentoo and ubuntu look identical; the decision between one and the other more comes down to preferred types of configuration and package management.