I'm aiming for a 5700/800x next month but one thing zen 4 could bring me is lots of preowned 5950x's
I feel the move to ddr5 is a mixed bag on the one hand ddr4 option would be nice on the other it splits the motherboard market something i feel amd doesnt want to upset as we now get a lot more motherboards to pick from.
The only real down side is if ddr5 will go fully mainstream and prices reduce on them parts due to mass prodution or if they will stay high.
I'd expect core counts to go higher once 3nm is possible as they will have the space and maybe more willing to just go higher across all the different use cases.
I'm intrested in zen 4 like all, but buying zen 4 might be a case of zen 5 or 6 for me after i get my little mitts on a new CPU and soon hopefully