partly because it is not modular. The git migration was
a migration to 100 fractured git repos, not modularized git repos.
If you want to modularize, then decide that that is a goal for Boost and I will help.
I am not entirely sure that perfect dependency structure would change anything. If you have 123 repos, it's gonna be painful no matter what.
I think the idea is that you then only clone the repository you work on. Thus if you contribute to 5 libraries, only 5 repositories are checked out. Each libraries would be independant in terms of building/testing... and it'd still be possible for scripts/tools to clone all 123 repositories and run tests on all of them. But that'd require quite a change in terms of how people are used to work with boost at the moment. Philippe