Unless you are wanting to begin a hard-core streaming career, where admittedly 4c/8t can struggle somewhat, the 7700K still does quite well in the large majority of games...as evidenced in this '7700K revisited' review at GN...
https://www.gamersnexus.net/guides/3423-intel-i7-7700k-revisit-benchmark-vs-9700k-2700-9900k
As I also have a 7700K, I intend to wait until there is at least a game in which the performance is left wanting (sub-60 fps?). As I've had this system almost 2 years, I'd not be surprised if I get 2-3 more years from it, frankly. I'm sure by then we will also be evaluating the GTX3060, etc...
(Naturally, someone rocking a 2080Ti might want 144 fps in some of the newest titles a bit sooner than me, so good luck...