It's not really that expensive. GitHub Enterprise is like $21/month/user while GitLab Ultimate was $100/month/user the last time GitLab published prices. These days GitLab Ultimate is "contact us for pricing" while the cheaper GitLab Premium is $29/month/user.
I guess Bitbucket is cheaper but you'll lose the savings in your employees bitching about Bitbucket to each other on Slack.
Do we work in the same company? That said, I really don't understand why everyone hates on Bitbucket. I really thought it was _fine_ from a user perspective. Now we're on GHE and I find it a sidegrade at best.
Now for the people who were operating Bitbucket, I'm sure it's a relief.
As a user, I found Bitbucket to be a lot harder when it comes to searching and browsing code. The Markdown formatting is also more limited for documentation and the lack of Mermaid support in Markdown documents was shocking to see considering how both of the primary competitors (GitHub and GitLab) have implemented it.
I guess Bitbucket is cheaper but you'll lose the savings in your employees bitching about Bitbucket to each other on Slack.