The replay feature lets players view their recent plays/playthrough, and even save/export or share them.
The option to save a replay is on the end-mission screen and you can view it later on the player profile (where your favorites are also located).
This could be helpful for players who want to record their playthrough
weird flexes but having problems with their screen recording application, example: input lag.
you could look at the replay feature of Touhou and osu! for reference