The Apple TV 4K (2021) earns an 8 out of 10 on our repairability scale (10 is the easiest to repair):

Modular construction and only a few major components simplifies repair.

The remote's battery and Lightning cable are soldered together—but not to anything else, so they should be inexpensive to replace.

The power supply AC-in jack is modular.

The remote itself can be fussy to service and it's guarded by pentalobe screws, but it's not glued together.

Most of the I/O ports on the streaming box are soldered to the logic board.