Would lock some current folks out of the game though. Some players I know sit in a wheelchair and as for me, I simply got no playspace for that, playing front-faced and seated, most of the time.
Played Dead and Buried for a while where you gotta do exactly that, duck and cower, dodge bullets physically and what not, had a mat in front of me to not bump my knees so hard, however I bumped my hand on the desk instead while throwing dynamite and it took weeks to heal… so that was it with that game and all similar ones
As for the first boss in Crypt, yah it looks fancy in the trailer, but no one would likely consider that even if it worked… it’s so much more convenient and safer to teleport to his side or behind. So it would need some other, new mechanics making roomscale movement more attractive and again, if there’s an alternative most would likely use that instead; and if there’s none, some would not play this content anymore.