@steel_for_humans My take on Ubuntu/Debian, no authoritative aspect to this opinion, other than, I have been using one or the other my entire time using GNU, with a few brief forays into Arch.

First, my direct answer: if you're liking Debian, and you don't feel limited by it, stick with it. Both Ubuntu and Debian feel exactly the same, and almost always you can follow Ubuntu instructions on Debian and have full success.

Debian's trip is basically conservatism - they want a rock solid, dependable system, and to achieve that, package upgrades are slower and permanently behind Ubuntu. Unless you run Sid, Debian's "rolling release" version, which gets you basically the same packages (and instabilities) as Arch.

You won't really notice anything different, day to day, on Ubuntu, so it is an equally valid choice, subject to your opinion of Canonical. I find their business practices... questionable, so I moved to Debian full time at some point, but notably, back in my one Linux job, I ran Ubuntu cause we needed it for some dependency or other. They were also the first distro to really do an implementation where the difficulty of installing and managing it was approximately equal to Windows', but nowadays you install KDE on any distro and you've got a very robust system.

Notably, Ubuntu has announced they're getting into AI implementations, with an emphasis on Local Inference first, so if you're not radically anti-AI, that would be a very good reason to choose Ubuntu.

I find that on the rare occasions that Debian's packages do not provide a thing I want, I can get it by installing an AppImage or Flatpak or (in desperation) Snap, or in cases of extreme need, it's really not that insanely hard to build from scratch, as long as the devs are able to write good instructions/scripts. There is no need to run anything else, at this point, from a functional perspective.

Bonus suggestion: for your servers only, consider having a look at FreeBSD. A completely different experience, and many would argue, a better one.

One example: If you are setting up a project that needs a web server, on Linux you are highly likely to encounter a thing where some people use Apache, some use Nginx, I don't even know what all is out there now for web servers, but there will be many different tutorials, and good luck to you in sorting out which tutorial is good quality, and uses the good quality tools. I have literally reinstalled systems in the past, for want of a good tutorial that was on the distro I had, but I'm the sort of weirdo who enjoys that.

Linux, fundamentally, is beautiful anarchy, which is difficult for the individual alone in the world. You are endlessly bombarded with choices, and little to no explanation of why you might want to use one thing vs. the other.

FreeBSD, on the other hand, has an opinionated choice on web servers, and the package they intend for you to use (which I believe is still Apache) is called httpd - ie, in the land of FreeBSD, there is one best web server, the HTTP Daemon, or httpd. The documentation of httpd is rich and lush.

You can still use the other ones, in general, but if you use httpd, you will have a straightforward deployment going in a very short time, because there is one canonical way to do it, and it's easily found in one place (the FreeBSD Handbook).

It does also kinda force you to learn how things work at a slightly lower level, BUT it does so, again, with good documentation that you can read and understand, and reward is that you do things in a far more computationally lean way, and get way way more out of your hardware.