This to me sounds like a break down of documentation and software architecture patterns, not so much a flaw of a monorepo. I’d rather it come up at that stage anyway even if it’s a pain, because it will help re-enforce better patterns and documentation as people feel these pain points. Shared libraries should have a code owner that is responsive for this if it’s not agreed that it’s straightforward enough to work on as an individual dev no?

That’s my take anyway