too expensive (the good ones)

too noisy

requires canvas for good experience

requires dark enviroment for good experience

requires either wiring on ceiling/wall and drilling or extra furniture under TV (short throw)

double power consumption over TV

the only benefit really is the size, but nowadays you can buy 65-75" TV which is already pretty huge depending on your room, so I fail to see argument for projector unless you need super large screen which you intend to watch from big distance/outdoors in very late evening