Azure DevOps is in a weird zombie state where everyone knows Github is getting all the development attention (and presumably most of the workforce now) but Microsoft is keeping it on just enough life support to keep companies "happy enough" and are still refusing to call it "dead". (They continue to point to the development roadmap, which is still actively maintained, but to some like me read very much like "bare minimum maintenance feature set". It also doesn't help that of the few open repositories for checking in on AzDO development, such as their community proposals repo, which are themselves hosted on Github, hah, it is very transparent most haven't seen active commits since 2019 or 2020.)

Bitbucket has a lot of Jira-integration and a lot of large corps are in Jira for the long haul now and "might as well get the synergy of Bitbucket".

Plus, don't underestimate the sunk cost fallacy factor keeping a lot of large corporations locked into things like Perforce and ClearCase.