7700K still cranks out VERY respectable gaming performance, usually outframing all Ryzen CPUs in pure gaming, although the 2700X comes close to matching in some newer games that do well with more threads....unless you wish to simultaneously stream, where the R5-2600X and/or 8400K and above can stretch their core and/or 'thread legs' to good effect, while the 7700K is then finally bogged down somewhat to the point of dropping frames, etc..
If a streamer, upgrade....
If not, I'd wait till this summer, as come mid-July, perhaps we will indeed find out if the 3000 series R5/R7 -3x00 8 core truly matches/exceeds the performance of the 9900K. (AMD is preliminarily claiming it matches the 9900K in Cinebench, which would be impressive indeed)