Another +1 for Perforce from me, it's just so much simpler for non dev users. It's of course a no-go if you really need the distributed nature of git, but as you say, for the majority of users that use GitHub/GitLab it's an option.

The philosophical difference I've found using both is that Perforce is file centric and git is commit centric. In perforce you have the file tree and then the history of each file, with git it's flipped. This is why I find it so hard in git to see how a particular file has evolved, with Perforce it's second nature. Perforce is so good at telling you why a particular line of code is there, I miss that so much in git.