i mean, writing the software i want to use is what i do when the existing software doesn't work the way i want and i cannot reconcile with the codebase to work on fixing existing software.

Put some logic to /etc/profile to ask user, passsword and session then set some ENV accordingly,

launch there as that user. (may be as swiching another therminal)

EDIT: write some cookie to somewhere or set some ENV to prevent that logic don't always run.

And yes, screw wayland

Lol, well we were all thinking it....

There are forks of console-tdm on github I think though and other such things similar.

I recommend looking in github for what you want.

And yes, screw wayland

KDE, Wayland and official NVIDIA driver worked just fine before, can't remember any issues with kwin.

I don't know if pointing to the graphics (3d, acce..?) helps; anyhow, best of luck!

why or how your experience with 'sddm' became so awful

SDDM is supposed to be able to run wayland-native, using either kwin or weston as the compositor. Neither work, instead locking up the TTY and producing absolutely no clues as to why.
I've already spent many hours (and many blind-reboots) on that and I'd spend more, if it weren't for the ridiculous list of other unaddressed bugs in sddm - frankly the thing appears to be a lost cause at this point... The KDE project seems to agree insofar as forking it so they can ship a reliable (though systemd-dependent) DM for their upcoming (6.8) shift to wayland-only.

Which is the exact opposite of what I am trying to achieve. I've repeated "without an Xserver for the display manager" more than once now, I'm really not sure why people keep suggesting X11-based DMs.
SDDM works fine when running on X, that's not the point, nor the goal.

To summarise, for my part 'sddm' is working quite well for my purposes; they're not very complicated, but on one pc I have messed about a bit with auto-login and some x11 glitches ignoring settings (it's on a daw) and all seems to work fine.
So I'm happy with SDDM.

Cheers,
Olav

console-tdm

Interesting, and appears to be pretty much pure shell too...
It'd be more interesting if the github page didn't have dead links to screenshots and unanswered issues dating back to 2021 though. Looks rather dead/abandoned to me, last commit was 7 years ago.
It also doesn't really look like a full display manager, more just a wrapper for startx to select an environment. Unless I'm missing something obvious, I see no login handling functionality at all.

(emphasis mine)
No "started by init", or "handle login" to be found, AFCocaineCT this is really just an app launcher in shell (which I would have written myself already, if that's what I was after), the user selection and login would still be getty.

Those all run on X, do they not?

The whole point of the exercise is graphical (or at least TUI/menu-driven) login and session selection, while not needing to run an xserver for the DM, which is kinda a prerequisite for the whole (somewhat dubious) "wayland is the future / x11 is deprecated" shtick.
That means either a wayland-native graphical DM that isn't both a memory-hog and a dog to configure, or a console TUI DM that can do the basics like presenting a list of users and sessions, providing power-off / reboot functions, remembering a users last/preferred session, and generally not looking absolutely awful.

Right now my short-list is lemurs or greetd+tuigreet. Both are (unfortunately and loudly) rust, but that's not a complete showstopper. Kinda hoping a not-rust equivalent existed, but so-so.

I consider minimal yet easy to use to be non-garbage which if so would mean console-tdm which isn't in debian repos to my knowledge.

But if you mean easy and user friendly, something like lxdm or lightdm or slim might fit.

Depends on which works best right now.

I honestly have no clue. Stuff breaks sometimes with upgrades in annoying yet minor ways.

I have however had no problem with lxdm usually and sometimes slim is good.

The Ly display manager
"A lightweight TUI (ncurses-like) display manager for Linux and BSD."

Sounds good on paper, until you realise "ncurses like" means "doesn't actually use ncurses, instead reinvents it in zig". It's not packaged in Debian, and while there are ebuilds for Gentoo, that just makes needing to install the whole zig toolchain for a text box slightly less annoying.

I was getting dangerously close to doing that myself, but between gathering patches from not-dead forks and a couple of my own, I think I might have got tuigreet into a mostly usable state. It's still rust and it's still part of the "1200 crates" ecosystem, which is irritating, but at least that's a toolchain I already have installed for firefox & co.

Honestly, this is all in service of my biennial "can wayland completely replace X yet / can you comfortably run a desktop system without an xserver installed" investigation.
The answer is still "not really" (unless it's GNOME, maybe).

Anything else?

You want me to make you one?