I don’t think what you are trying to achieve is worth the effort TBH. It would be easier to just grab Arch or Artix base, or Debian and remove stuff from it, especially since you want the Linux-zen kernel.
If you want a better gaming experience, you should probably look into lighter desktop environments, like jlittle mentioned. One pretty lightweight combination I went for when I used Arch on my work laptop (don’t judge) 3 or 4 years or so ago, was to install LXQt and replace Openbox with KWin for the eye-candy and other performance tuning from KDE (and used latte-dock, because I couldn’t stand not being able to use my old Super+[1-9,z-.] key combinations to switch between programs. The CPU utilization was minimal and RAM didn’t go above 350 MB, probably even less since LXQt with Openbox barely touches 130 MB and I know a light Plasma desktop doesn’t go above 400 MB.
There is a difference and somewhat of a compromise between minimalism and performance, when it comes to software development, but not necessarily mutually exclusive. What I mean by this is that you could “debloat” your system (whatever that means to you) and still not achieve a decent gaming performance. For example, if you go with a custom kernel that removes everything to the bare minimum for your hardware, you may miss on some performance tuning options that add a bit of bloat to the kernel, but make the system feel smoother.
In another example, using just a single-threaded Window Manager will be very minimal, but at the cost of screen tearing and potential stutter or frame drops. I would guess i3wm and sway are pretty performance optimized, as opposed to something like dwm which keeps the code minimal. It is very clear that dwm is the less bloated choice, but I would guess you would have a better time on i3 or sway.
One thing to note, I was using JWM + Compton on my raspberry pi, which worked, but screen tearing could still be observed in video playback, but when I moved to sway, everything was smooth. Wayland is just that good if you can get away with running it. I never managed to get KWin_Wayland and LXQt to play together nicely, so I only used Xorg KWin with LXQt.
Both GNOME Shell and Plasma5 have Wayland sessions, but I would argue that if you want a minimal setup to give more resources to your games, you shouldn’t use those. However, I would strongly argue that if you have the girth resources to run GNOME Shell or Plasma5 and you prefer a more featureful desktop environment, use those instead. I have ran KDE Wayland on my previous computer and I can say, while it was a bit unstable after 2 weeks or more of uptime, the perceived smoothness was great. I didn’t play games on it however, I had a Windows VM for that. But that was like 2 years ago, so I would guess a lot has improved in KWin_Wayland.
Then, there will be the new cool kid in town, SteamOS 3.0. It is using an Arch base and I would guess Valve would allow the user to break his own system if one wants to dig into it, so instead of trying to make a distro now, maybe you should wait for this to launch. I don’t really like the hype around the SteamDeck, mostly because everyone talks about it to death, but also because while the hardware is cool and all, there is not a lot of emphasis on the OS itself. It’s Linux! So potentially anyone could make an alternative to the Deck or a DIY steam machine (those are 2 words you probably haven’t heard in a long time) and slap SteamOS 3.0 on it. And I would assume the Valve engineers may be putting at least some effort to make the OS more optimized for gaming.
Even though I kinda despise Arch (mostly because it’s been so unstable over the years, with Manjaro taking the cake in that department), I’ll probably be trying SteamOS 3 if I’m going to get another x86 computer, although I’m uncertain about that. I haven’t seriously tried Artix, but some issues I had with Manjaro and Arch were due to systemd (things like not unmounting file systems or network shares), but I did have Arch completely bork itself due to a motherboard or RAM failure on my work laptop and when I moved it to a known working laptop, I couldn’t get Arch to work properly, the root FS was K.O., so I slapped Fedora on the other laptop, as I was in a pinch to get it working and go back to work (and enjoyed it).
Speaking of which, besides SteamOS, the only other distros that I would personally run if I were to get back into gaming would be Fedora, Artix-s6 or Pop!_OS, in this order. As general purpose distros, I like Void and Alpine more, but I mostly use the musl variants (well, Alpine is musl only). I know people ran Void with glibc for gaming and enjoyed it, but I would guess it will need quite a lot more effort to get it to run linux-zen and probably getting other software, like Steam going (I haven’t ever enabled the proprietary repos, so I don’t know what’s in there, but now I’m on ARM, so I have even less of a reason to do so).
I remembered I haven’t addressed the minimal software aspect when it comes to CLI tools. You only use sudo when you update stuff, so there is no reason to refer to sudo as bloat when it comes to a gaming distro, because tools like sudo and other CLI tools do not impact your system’s performance. They only run when you execute them, then they terminate, using no system resources other than storage.
I do use doas (and yes, I do see it getting updated from time to time), but I do so because I have no need for all the sudo features and because my distro easily allows me to ignore dependencies and remove them from my system, sudo included. And because I don’t want to login as root, I prefer staying in my own shell (ksh) with my own colorful options and display settings, and changing the .profile for the root user is not recommended (although the default shell for root is dash, so should technically be fine).
I do agree that on a distro like Arch and Debian, and to a lesser extent Void, you will find a lot more tools preinstalled than you will find on a distro like Alpine. But those do not impact the performance of your system. What does impact the performance is services that run in the background, which is why I don’t like Ubuntu-based distros, I don’t know what they do, but they got too much stuff in the backend.
