There are billions of possible hardware configurations and billions of use cases for an OS. No OS will ever be able to work on all of these combinations flawlessly, I’m just saying that on average you have the best chances of everything working out of the box if using Ubuntu and even if not, there are the best chances that you find help online for your problem on Ubuntu, but there are of course cases where other distros will be better suited.
While I personally am a big fan of Arch, it’s absolutely not for beginners.
For a normal Desktop user nowadays I think Linux is just not worse than Windows. Don’t ask what Linux can do what Windows can’t, ask what Windows is doing what Linux isn’t: Spying on you, installing software you neither want nor need, forces you to use software you don’t want, forces you to connect your local account with an online account, forces recent hardware on you and in the future, forces you to move all your data into the cloud. And all that while charging you a few hundred moneys. Linux just doesn’t do that (well, depending on the distro of course).
For newcomers and non-techies I’d recommend Ubuntu or Ubuntu based distros. Plain Ubuntu is the distro which in most parts ‘just works’. If you’re looking for something which looks more like Windows have a look at Linux Mint Cinnamon. Linux Mint Mate (or XFCE) is a great choice if your computer is a bit older. I also mention Kubuntu because KDE is the a very popular desktop but rather demanding (but also feature rich), it may also feel more natural for people switching from Windows.
All of them will run Steam without trouble, but be aware that playing Windows games on Linux can in some cases be troublesome and require manual fixes. Maybe look beforehand which games are supported how well on https://www.protondb.com/ .
Debian is not easier than Ubuntu, the opposite is the case, you have to tinker around with some things to get them work how you want them. Usually you end up with a system which is more suited to your needs and preferences, but you have to put more work into it.
In terms of stability, it’s not like Ubuntu LTS Desktop will just break down, I use it way over 10 years and it never end up in a broken state (well it did, but it was my mistake). It’s more of a server thing, were you can just install updates without having to fear that something got incompatible.
From the software part, I think this is only an issue if you’re a developer. If you want something like the most recent LibreOffice, you can just install it via Flatpak. A bigger issue arises if you need something like a more recent Python or GCC.
From the hardware part, you should of course always check beforehand with a live distro if your hardware is supported. Debian 12 however is very recent and should support most recent hardware and it will keep supporting it unless you upgrade e.g. your GPU.
LibreWolf is a Firefox fork with features removed which we don’t want (Telemetry, Pocket, …) and a few (privacy) features enabled (which can be deactivated if they’re too annoying). I didn’t had any issues with Firefox extensions as well.
I’m currently using it on Debian and it runs smoothly. Recent Ubuntu versions are also supported and you can install them via your package manager, see here.