You have UNIX history? I started with V6 at U.C. Berkeley in 1976. I have a few contributions in the BSD fortunes file.
The decision to avoid systemd and Wayland is sensible. There are serious issues with both and they represent wrong turns in the history of Linux.
There are standard Linux distros that might work for your purposes. Devuan comes to mind. Devuan eschews systemd and prioritizes X11/Xorg over Wayland. And it's essentially Debian, so everything important runs.
If you're an old UNIX hand, Slackware might be the AINeko's meow. Slackware was my first Linux distro in the early 1990s. For all intents and purposes, it was UNIX. I actually migrated my company [a software development firm] from SunOS and Solaris boxes to Slackware running on 486s.
Today, Slackware uses a BSD-like init system [instead of systemd] and treats X11/Xorg as the default. Wayland is supported as an alternative.
PCLinuxOS and Void Linux are two other options. However, I haven't tried those distros.
For what it's worth, my own Linux distro [30 years old this year] eschews both systemd and Wayland except for the minimum core Wayland libraries required to compile some packages.
On cloud servers, I run #Devuan because host dedis are able to boot it. From there, on the dedis, I run my own distro in an ultra-light container.
If you prefer a light Linux experience, you're far from alone. Most developers that I know directly do as well.
In a humorous note, one of my students once asked me to name the smallest thing in the Universe. "Planck's Constant", I replied. It turned out that he wanted to create the smallest distro possible. Thus was born Planck Linux.
I think that that distro fit on one floppy. Note: It isn't online any longer as the developer is presently working on a distro that is intended to be slightly larger.
In regular FOSS now, it's considered acceptable to have terminal emulators that require hundreds of megabytes of RAM.
For the sake of dancing icons and such, too, desktops now pile layer upon layer of unnecessary software until the result resembles the 100-layer dip shown in the attached screenshot. The end result isn't small or fast.
I'm not able to fathom the mindset.
My desktop core has taskbar, workspaces, systray, alt-tab, launch buttons, live dockapps, live wallpaper, start button, multiple terminal options, volume control, offline Wikipedia, and single-instance support. Does anybody truly need more? Additionally, response times even on a decade-old laptop are, blink, you're there.
The punchline is that the core consists of a single fast executable of about 300 KB plus a few support executables and scripts. KB and not MB.
That is how it's done.
My advice to people is to seek the light. A light Linux, that is. BSD is fine, too, but #Linux distros might be more complete and come with larger communities.