> 2- Isn't it better to use a login manager that is 1- graphical and 2- uses the same GUI tech as your DE

A text only login manager could spare some more resources on small systems, since once the desktop environment has been loaded it keeps running anyway. I use LightDM and XFCE for example, and if I look at LightDM memory consumption, the amount although not huge is neither trivial; I guess small embedded devices would benefit from this.

  $ sudo pmap `pidof lightdm`

  2021:   lightdm --session-child 14 23
  000055728c276000     28K r---- lightdm
  000055728c27d000    168K r-x-- lightdm
  000055728c2a7000     76K r---- lightdm
  ....
  ....
   total           163696K
  1795:   /usr/sbin/lightdm
  0000555cca10b000     28K r---- lightdm
  0000555cca112000    168K r-x-- lightdm
  0000555cca13c000     76K r---- lightdm
  ....
  ....
   total           236188K

1: You can login and not start up a display (e.g. when you SSH into a box). The login manager is seperate from the display manager. You don't necessarily have to have a display attached.

2: The display manager starts up a window manager, which figures out where to draw your apps. X11 or Wayland is the underlying tech that KDE, Gnome, etc, uses to manage displays/windows.

Ly draws straight to the terminal, which I'm pretty sure is faster. And it allows some flexibility when running multiple window managers. I've found having multiple window managers installed can be a little unstable. SDDM didn't like it, but it works pretty good with Ly.

> 2- Isn't it better to use a login manager that is 1- graphical and 2- uses the same GUI tech as your DE

You're assuming everyone using Linux uses a DE.

1. I think the term comes from X11 jargon, where each login session is associated with a display (the thing described by the contents of `$DISPLAY`.

I'm interested in trying this out with i3. I've only just started using i3 and the default lightdm display manager (on NixOS) looks and feels out-of-place with it. Ly seems to be a logical next step.

Are you the only user? Do you always use i3?

If yes to both, you could have your bashrc (or you shell's equivalent) start X and i3 on a TTY login?

https://wiki.archlinux.org/title/Xinit#Autostart_X_at_login

An even more lazy approach is logging into the console,

regardless if textmode or framebuffer,

and simply do upward arrow & enter,

since whatever starts your session is the last entry in shell history anyways :-)

This way there is less surprise/annoyance with flickering/crashing X,

like you could have when starting X unconditionally after login,

which could happen after you modified something to test.

On another console, to not spoil the history for that upward arrow & enter thing ;-)

Which works regardless of shell/WM/DE/OS/whatever, at least it does so for me.

Is this an approach that works well with screen locking, or is a display manager really necessary for that feature?

You don't need display manager to lock screen in i3. Just run or bind a key to run i3lock (or other lockers like slock)