they're cloning github. it isn't rocket surgery. most of the hard technical work was done by github itself, when they built and released libgit and the other core pieces of their stack.
in many ways, that's the whole problem with this conversation: coding doesn't have much room for professional advancement, because 99% of the available work can be done by inexperienced kids.
I'm not sure he's trolling. For the sake of discussion, are the features you mentioned actually "hard technical work" or is it just work that can be done by anyone with some experience in that field?
I'm not sure how to define "hard technical work" but I would say that it has more to do with the rarity of people capable of solving a problem rather than the time it takes to solve it.
That's not to say Gitlab's work doesn't have value, the only question being if it really falls under the "hard problems" category.
in many ways, that's the whole problem with this conversation: coding doesn't have much room for professional advancement, because 99% of the available work can be done by inexperienced kids.