They've made a lot of progress in the recent years, and the last two major releases downright feel snappy compared to GitHub (really, browsing a repo tree is literally snappy). Oh, and their SPA implementation actually works, the back button is not broken 90% of the time like it is on GH.

And mind you, that's on a small 4 core VM on 2019 mid-range Xeons, which I would not consider to be a huge amount of compute (granted, not Raspberry Pi level, but I'd expect the SD card to be much more of an issue).

So yeah, along with the sane(r) way to do CI pipelines, and usable review tools, it's a net improvement over GitHub.