"So breadth over depth is the strategy for GitLab the company. GitLab the project should have depth in every category it offers. It will take a few years to become best in class in a certain space because we depend on users contributing back, and we publish that journey on our maturity page. But that is the end goal, an application of unmatched breadth and depth."
Now my experience is exactly the opposite. I like all of the things GitLab does, it is an obvious and significant value add but ... when I have experimented with it in a home lab and elsewhere there were several things which gave me pause, and I've seen the same expressed elsewhere which alleviates doubts I may be wrong.
Now I'm in the position where I like something and hesitate to recommend it worrying that the details will make my life more difficult and my users' lives more difficult and not less, not because of missing big features but because of quality and depth, as you call it. Maybe it's the right thing for your business to go for breadth even for years longer and seek depth in the future to solidify your position. But for now, as a potential user, GitLab might not be right for me, which I think is unfortunate.