What was wrong with SteamOS being based on Debian? I’ve not used SteamOS myself, but I wasn’t aware there were problems in that regard.
That could have saved some time on tooling/packaging adaptions.
Not that I dislike Arch Linux, I run both Arch Linux and Debian (Stable on servers Sid on laptop).
Not only is having new stuff good from a feature and hardware-support standpoint, but, paradoxically, new software seems to have WAY less bugs than old software. (I assume this is because devs are mainly on the new versions and don't care about old versions that much.) Try using CentOS 7, with ancient, should-be-rock-solid versions of apps. Dolphin crashes every time you load into a large directory. Kate's keybinds are broken. Tmux refuses to support 256 colors. I get none of these issues on Arch or Manjaro.
I'm also sure that Valve's system is going to have a smaller set of software than I'd use on an Arch desktop anyway, so there's less surface area for stuff to break.
Maybe the people using lots of AUR are complaining a lot, and the people who don't just quietly switch distros?
I'm sure that Valve is going to install a much smaller set of core software than a typical desktop, though.
I have the exact opposite experience, I used to use sid and had to do full-blown reinstall every couple months because e.g. dpkg would break too much and I wouldn't be able to install anything, or once, even boot and ended up migrating to arch despite the warnings - never had to reinstall the distro once since then
That said, never had to reinstall either of them. Had my system broken by pacman in ways dpkg would handle much better, but it was fixable anyway.
With the opi package you can install: chrome, codecs, dotnet, msedge, msteams, plex, skype, signal, slack, teamviewer, vivaldi, vscode, vscodium, zoom and more.
Brave is app i am missing so far, but having the newest version KDE and other software that required a PPA on Ubuntu is pretty nice.
And it feels much snappier installed on a SATA SSD than Mint from a NVME SSD on the same machine!
The auto-snapshot feature on updates was really cool, and direct integration then (almost 10 years ago for me) was ahead of most other distros IMO.
I then setup Arch to be more confronted with the things that actually go on under the hood, learned a lot and had generally a good experience with it. A bit later I got a job where Debian plays a key role, that sealed the deal on using Debian and Arch only for me (remembering the usage of two package managers is enough for me ^^).
But I have good memories of openSUSE, and it was the distro that I first used "full time", even introduced me to Linux to some degree (I dabbled a bit around with Ubuntu and Knoppix before).
(My go-to though)
Debian is in general really rigorous with ABI/Symbol versioning, dependencies and packaging in general - there are some outliers, but most of the packages in Debian is just high quality work.
On the other side is Arch Linux, where they do not even care about Kernel ABI bumps, which are trivial to detect and track, so if you pull in a kernel update you cannot load any new module, as they just overwrite the modules of the running kernel - I used it, but I find that still lunatic!
Nothing like having some complex workspace setup and then needing to connect to a VPN/WireGuard network but also forgetting to preload that module (I just load all possible relevant on start nowadays), forced a reboot, nothing lost but tedious.
On Debian this and other things where you're in limbo while some library version mismatches, or some AUR package is depending on another one, won't ever happen on Debian. It has its disadvantages, but they certainly dot their i's.
Arch is still a better choice because gaming is generally using cutting edge software.
It works great if you mostly stick to official Debian packages through and through.
I need external repositories (albeit rarely) with Arch too though and that has never caused a problem.
If you want iPhone ease Linux use Ubuntu based distros. But traditionally Linux hadn’t been single click easy. Much like smartphones weren’t originally iPhone level easy.
Polite edit: if you’re a Linux noob start with a vm or live disk Ubuntu image and play around. If you like computers and understanding them, you’ll find the lessons you need as you need them by searching the web. Then you’ll install a bunch of distros and understand what I mean.