It's your work and it's good to own that and also it helps get your name out there if you want to dive further in to Game Development as a career specifically.
There's other reasons as that long talk by Foddy and Gage goes through but that's the main gist.
EDIT: Top comment on the video exemplifies this fairly well.
"I literally clicked this video because i knew who Bennett Foddy was thanks to Getting over it... So it really does humanize the game devs in a special way and makes the users care about the devs."