Higher core counts are indeed already greatly appreciated in workloads that can use it...Cinebench, encoding, Handbrake, the list goes on...
But from a gaming perspective, 7700K users will likely be left standing pat a generation or two at least, until something can surpass it. (currently, the 7800-7900 cannot) It will be an interesting next 6-24 months...
I am fully aware the gamer/ streamers are getting great performance on R5-1600/R7-1700...