Sometimes I end up on Bitbucket pages for a repo, and have a hard time locating how I can view the directory tree of the repo. I wouldn't call this "superior." It's not unfixable, but definitely not superior.
On an unrelated note, I gave up on GitLab last year because the landing page always showed recent commits instead of the readme, making it less welcoming to new users who just want to see what the project is about.
I'm glad to see they have changed this; navigating to a GitLab project now shows you the readme. Definitely going to give it a long hard look to see if I can switch again.
It really depends on the mindsets of users. My guess is that Github users tend to browse/read code in multiple repos more while Bitbucket users tend to work on their own private repos more. So it's logical that Github defaults to source tree while Bitbucket defaults to commit history.
