Game versions are locked to a specific console, on a generation with some faulty hardware. The trend nowadays is to re-release games for newer generation.

The re-release is technically a different game, so it might require another music license, so it might not have the same soundtrack, it changes the feel of the game.

The old console has its time ticking.

Without emulators, that game experience won't be preserved, its simply at the whims of executives which don't really care enough about such small details for re-releases because the name of the game is usually enough to make some bucks.

No, they have publishers that release updates which just make games worse.

The 360 version of GTA San Andreas was originally a backwards-compatible download of the game as it existed on OG XBOX, but some years later it was “””updated””” to a console port of the smartphone port of the game, losing many music tracks in the process. Everyone lost their saved progress too since the new mobile version wouldn’t read the old saves.