Gitlab used to be about as reliable as github. (ignoring the security oopses they used to have)
They simply don't have (or didnt) the skills to scale. THey were talking about using ceph to run things (which gives you an idea about how green their infra team was)
Are you implying they should create more in-house solutions, or that specifically Ceph is not a good solution and there is some other 3rd party solution that could be used instead?