This all depends on your viewing preference. If you prefer to sit close, a monster screen can actually be pretty jarring on the eye - and the image quality may look poorer. If that's the case, opt for a much smaller TV around the 32ins mark, or even better a monitor. If the PS5 is plugged into your main TV in the living area, and you prefer to game at distance, 55ins is definitely recommended. It gives you tons of size without overpowering the room or blowing up the 4K image to a point where quality suffers.