Because playing games designed on CRTs on a modern TV and at modern resolutions is an objective visual downgrade in almost every single case, except for a tiny select few cases.

Ii don't think it's replicating it for the shake of it. It's more, kind of, to experience pixel art closer to the way it was designed.

It depends. Graphics weren't spiky pixels as you can recall. That produced a far softer image, aside from scanlines and all the other stuff.

By now I can hardly play retro games from that time without shader, since the impression is auch a difference.

And I always was a pc player (from 8086/8088 on) and my consoles from mega drive on always used scart.

Still.