I'm not sure why monorepos are in the list. Care to elaborate?

I've worked on projects that used a single repository for all the code written by different departments and projects where the same department could have multiple repositories. The later added insane amount of busy work, inordinate amount of errors, difficulty to investigate failures, excessive use of resources to house various permutations of systems created at different times with different combinations of components. The day-to-day in such projects could be described by developers waiting for the infra people to sort out the morning problems which mysteriously broke everything all at once so that no progress can be made.

This was in stark contrast to companies working on a single repository, where days when nothing worked would happen maybe once or twice a year.

I also lived through transitions from multiple repositories to a single repository and the other way around. In operational terms, I've never seen any beneficial effects of splitting a repository. Not in the short, nor in the long term. Complexity always went up, productivity went down, general satisfaction with project infrastructure would also go down with such a change. Department would start attacking and blaming the infra people for creating obstacles to their progress (while never explicitly mentioning the split repository because, usually that was a decision made by the same people complaining).

The absurd lengths people will go to avoid learning how computers actually work because they fell for the buy now, pay later promise of 'easy' development.

Talking form a perspective of someone who worked at Google and one other similar company that shell remain nameless... as well as simply looking at places like Github where people tend to post projects they are working on: I don't know of any Github project that would be even in the size range to cause any discomfort for a laptop user.

Even when it comes to the larger projects: I have multiple checkouts of GCC and Linux kernel on my laptop, and when I run du their existence doesn't even register in the first dozen results... Of course, proprietary projects tend to be on a bigger side due to putting a lot of not-strictly code-related stuff in a repository, but still... it would have to be billions LoC big to be prohibitively big for a typical laptop.