They're losing to GitHub. While they advertise that they have 2/3 of the self-hosted git server market share, they just barely have a double digit share of the total VCS market, which is where the real enterprise money and value is. I don't have figures on hand, but I'd guess they have a single digit percentage of actual enterprise market share. GitHub has the same domination over its space that Google has over search, and Microsoft is excellent at competing on enterprise partnerships.
Tech companies usually scale out their products eventually anyway, but in GitLab's case it's probably existential if they want to maintain status as a high growth, VC-backed company. They need to find another of their competitors' moats which is easier to chip away at, or they need to change the game and introduce something original.
In my experience their approach to pipelines and CI is a winner. In that regard GitHub seems to be playing catchup and the "checks" feel like second class citizens in GitHub while it feels really cohesive in GitLab.
I do question the “kitchen sink” product strategy and whether it’s sustainable - Atlassian pulled it off by building a product line rather than an all-in-one.
AWS, on the other hand, is 500 different massive bloatwares that are scary to touch, to the point where there are literal courses available so you can learn how to use them. I've never had a good experience doing even basic stuff there.
It turns out, if you host the source, you hold the keys to the world of DevOps, too. It is completely natural then for GitLab to venture in to an ever expanding field of GitOps and eventually the Cloud computing market. I mean, Microsoft plonked billions on GitHub for Azure more than anything else.