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.
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.