Yes, there's historically been cases for dynamic typing that went beyond "writing type annotations is hard", although as time has progressed, computers have got

Yes, there's historically been cases for dynamic typing that went beyond "writing type annotations is hard", although as time has progressed, computers have gotten faster, and compilers have gotten better, the scope has gotten smaller and smaller. (I think a language in Python's niche that was created today would have a simple type system with extensive inference, just because someone developing such a language today would find it technically feasible.) Another case is what Alan Kay calls "extreme late binding" in a messaging-oriented language, as seen in Smalltalk and Erlang.