GitLab is no improvement over github, their features are frequently half-baked, their site is slow, and outages are just as common.

I used to like Gitlab, and I've self-hosted enterprise versions of both github and gitlab, and strongly believe migration from one of them to the other for "improved reliability" will be utterly underwhelming and pointless.

Gitlab used to be able to take the high-ground due to the open-core model, but these days I'm not even sure if that makes an appreciable difference.