(Not op)

it typically offers better video processing and upscaling, more accurate color reproduction, cleaner gradients, and superior HDR handling (including dynamic tone mapping on some models). Many also support Dolby Vision from UHD Blu rays, which the PS5 does not.

It won't show on a bad screen that much, but a dedicated player will squeeze out more of the disc.

There's a bit of misinformation here. At the end of the day, a blu-ray player is reading information from the disc and passing it onto the TV digitally - one player or another are going to do that identically. One can't have 'better color' or anything like that.

HOWEVER, there is an exception: Feature support. For example, not all blu-ray players support 4K blu rays. Not all players support Dolby Vision.

If you try to play a 4K blu ray disc in a non-4K blu ray player, it won't function at all (won't read). If you try to play a disc using Dolby Vision in a player that doesn't support it, it will fall back to HDR10.

But assuming 2 players both support the features a disc uses, the end output will be identical.

There's also upscaling, which some players can do differently.