> I've witnessed having those packages and versioning only lead down to unmanageable dependency hell.

There is no dependency hell. Your consumers allocate work effort to migrate to the latest version. This is work you would still have to do with a monorepo.

In a monorepo it would be much easier to find out who the consumers are in the first place - how they use your APIs, and you could easily create a single PR that the consumers can review and approve.

In my experience, with separate repositories, packages and teams, I think it's a huge challenge to get e.g. 8 different teams together and then to agree to migrate, since everyone's roadmaps are probably full for the following 4 quarters already.