I personally couldn't really name one but it is many small incremental improvements adding up to something bigger.

When a place I used to work at mandated a switch away from GitHub to GitLab I was a bit annoyed and saw it as penny pinching, going for the cheaper but crappier option, but since using it daily for a while I am a convert. I have my own installs of the free version running in some places now as well, and I find that pretty painless.

Their CI tool is nice as well, dead easy to get started with.