I use Github for 4 reasons:

• Everybody else is on Github. Github is to repo hosting what Youtube is to video hosting. It's sad but that's how it is in this world of unchecked, extreme big tech monopolization. So I put my stuff up there because it's just simpler to be found.
• I use Github as a dumb git repo. I don't use any of the extra social media garbage Microsoft tacked onto it. So I get free hosting and Microsoft pretty much gets no data on me - i.e. I'm a net loss to them.
• You can use dumb repos as PPA and RPM sources, if you need to distribute Debian or Redhat packages. Microsoft never intented for repos to be used this way, but if I can abuse Microsoft services, I will six ways to Sunday.
• Github lets you drop videos in your README.md. But here's a trick: you can use the links to the video files anywhere. In other words, you can use Github to host videos that you can post on other forums - including here on Lemmy, or on Reddit if you're still patronizing that cesspit for some reason. I find this a nice way to abuse Microsoft's resources also, and I'm all for abusing Microsoft's resources.

TL;DR: I use Github not only because it's the most prevalent git hosting service out there, but because I can abuse it and make Microsoft pay for the abuse without getting anything of value from me in return.