I will never not shill for physical keyboards on phones. The Droid 4's keyboard could be used with a PS1 emulator, I remember replaying FF Tactics before Square officially ported it.
That port by the way, one of the good mobile games.
There are some pretty decent portable controllers out there though (I.e. Turtle Beach Atom). Plus phone brackets for Series S/X controllers and DS4/DS5.
So there are good controller options, touchscreen controls for games designed for physical controls suck.
But carrying around physical controllers isn't very convenient.
I've plugged an Xbox controller into a phone before and that worked. I've not had an iPhone since they moved over to the USBC so I don't know about that.