The challenge I see most is getting the right level of understanding and design freedom to the developer level, where they know why they're being asked to do some work but without burdening them with extraneous detail or processes.
A lot of developers get annoyed at project managers and architects but they dislike project politics even more.
If a PM or architect is annoying developers then there's a very big problem with the PM or architect. Like any profession you get good and bad apples. It's why anonymous feedback from people who manage you and whom you manage is so useful. Of course ego is prevalent the higher up the chain you go so this is something many organizations won't do.