Controlling terminal of a display server

When I login on a Fedora 31 workstation and run the ps command, I see the below output;

for an X session:

 PID TT   CMD
...
   1 ?    /usr/lib/systemd/systemd --switched-root --system --deserialize 29
...
 820 ?      /usr/sbin/gdm
1305 ?        gdm-session-worker [pam/gdm-password]
1346 tty2       /usr/libexec/gdm-x-session --run-script /usr/bin/gnome-session
1348 tty2         /usr/libexec/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -background none -noreset -keeptty -verbose 3
1444 tty2         /usr/libexec/gnome-session-binary
1465 ?              /usr/bin/ssh-agent /bin/sh -c exec -l /bin/bash -c "/usr/bin/gnome-session"
...
1316 ?      /usr/lib/systemd/systemd --user
1322 ?        (sd-pam)
...
1531 ?        /usr/bin/gnome-shell
...

for a Wayland session:

 PID TT   CMD
...
   1 ?    /usr/lib/systemd/systemd --switched-root --system --deserialize 29
...
 825 ?      /usr/sbin/gdm
1309 ?        gdm-session-worker [pam/gdm-password]
1351 tty2       /usr/libexec/gdm-wayland-session /usr/bin/gnome-session
1356 tty2         /usr/libexec/gnome-session-binary
...
1321 ?      /usr/lib/systemd/systemd --user
1327 ?        (sd-pam)
...
1492 ?        /usr/bin/gnome-shell
...

As I understand, graphical logins via a display manager like gdm executes an X/Wayland session directly after authenticating a user, instead of executing a login shell. I see that both X and Wayland sessions are started on a virtual terminal (tty2), and what the Xorg(1) says about the vt option is: 'This option applies only to platforms that have virtual terminal support, such as Linux, BSD, OpenSolaris, SVR3, and SVR4.' Is starting X/Wayland sessions with a controlling tty done merely to provide the ability to switch to other virtual terminals while running a graphical shell in one, or is it a constraint of X/Wayland? Is it possible to start an X/Wayland session without a controlling tty on Linux, and is this up to gdm, X/Wayland, or systemd? And what would be an example of a system that runs Xorg and doesn't have virtual terminals at all unlike the systems listed in Xorg(1)?

I'm not quite sure I got your question, so please be "understanding" if I misunderstood you.

All *nix based systems have multiple TTY's, usualy 4 but can be 6 or 7 as well.
This includes Fedora

(Simplified)
Other than how they work (backend-under the hood) to provide the GUI, Wayland and Gnome are no different to each other, same for any other GUI/WM/etc....

At any given time - unless you somehow managed to freeze your system - you ALWAYS can press "CTRL+ALT+ {F1...F7}" to switch to the speficic TTY1 - 7.

If I remember correctly, most *nix based distributions use TTY2 or TTY4 as the default GUI-TTY, while the other TTY's could be used for other things - regular console usage, with the exception of TTY1.

And something to clarify, a GUI is not the OS (any *nix, incl BSD etc, Mac, heck, even Windows), this said, both, Gnome and Wayland have the same compatiblity to the underlying OS, this includes - but is not limited to - how they get started from a TTY, as they both rely on the same services and methods.

Hope this helps

If it does not, please wait for someone else to respond or rephrase your question.
Thank you and have fun!

@sea I appreciate the effort Don't hesitate to ask for clarifications on the questions I asked.