TVs should be turned off completely when you press the button, to save power. After that almost all smart TV boot up quite slowly. Which is sad :(
Oh, usually once a week, sometimes twice a day, the phone will do the rebooting for me. Sometimes when it's in my pocket, sometimes when I try to watch a video that's just too long. Maybe some kind kind of memory error?
What you said reminded me of this, because I had forgotten this infuriating rebooting. I wonder if this was related to the building or something else? This is weird.
Rebooting your phone is an uncommon use case, so it's not optimized.
KDE used to load a session in the background when the login screen showed so that you didn't then have to wait after logging in.
On Android without root the system seems to use a ton of resources on background jobs that aren't needed; I imagine that slows boot too.