There is something to be considered here, in relation to "real world" PC configurations. For instance, if you look at the Steam info on current systems, you see that the majority of systems and the largest player base are still WELL behind the curve of current technology. Now, this doesn't mean that what you buy today isn't soon obsolete, but there is a plus side to game and app/program developers to keep the top of that bell curve "current" as well.
In my own case I used to wait 4 generations or 30% uplift in performance. For a long time that was a great value proposition for keeping a somewhat relevant system. Just in the past few years we have seen a lot of innovation in the market. As much as I would like to say that the current rate of innovation will continue....what if it doesn't?
AMD made an amazing, game changing product back in 2017 and have been building on that. Intel is having issue getting off 14nm, and they are among the most currency liquid companies in the world. Where will the market be in 2/4/8 years? Who knows?
Speaking for myself I will likely want a new toy before that long anyway.
With all that windiness over (lol) I think that gaming performance tends to favor the 6 core to cost/performance right this moment. They are a GREAT value proposition. When you add the productivity aspects, in my mind I say go for the gusto with the budget you are willing to put forth and worry about upgrading again when you feel the time has come.
Your rig will likely be relevant long after that point. (at least in my experience)
.02