However those orgs often have a Very Big License for GitHub Enterprise, and therefore with some enterprise porting tools it's not that high friction a switch (supplier managers will be all in favour; one less contract to manage!)
Yeah. We used to pay for GH Enterprise and run Jira/Confluence/Bamboo/etc/etc.
Then we switched to BitBucket Server because it integrates better and cost a lot less, plus GH Enterprise was a weird black box VM back then that we had to hack into to make work for whatever reason.
I couldn't point you to anyone who likes BitBucket Server, but as long as you're on the CLI and don't have to use the terrible web UI too much, it sort of works.
I much preferred Bitbucket Server to Bitbucket Cloud. For context, Server is an entirely independent codebase to Cloud (not even a fork, just completely separate products).
However those orgs often have a Very Big License for GitHub Enterprise, and therefore with some enterprise porting tools it's not that high friction a switch (supplier managers will be all in favour; one less contract to manage!)