I still host a significant part of my code on GitHub, despite moderately hating Microslop, because:

• Their CI is mature and super fast. My gorgeous instance has selfhosted CI, but some actions only work on GitHub (release-plz has bugs for forgejo), and their CI servers are fast as fuck.
• Visibility. People look for code on GitHub. Maybe maybe maybe they look on code on Codeberg, but without a doubt, nobody looks for code on my selfhosted forgejo instance. I am looking forward to forgefed integration sonce over a year, but it's not there yet.

Also, GitHub has become an identity provider for many services, such as crates.io to release rust crates (packages).