Thats my problem as well, as I only use the machine I am typing this on for gaming and there is no benefit for me swapping from a 7700K to either a 9900K, 3x00x or 3950x.
The games I mainly play barely use the cpu to 100% at 1440p other than Division 2 and Destiny 2, but Elite Dangerous only uses my cpu to 40% and the gpu to 60% to 80%, so for me it's just a side grade for a stupid cost.
When games start to struggle because of the cpu then I will think about an upgrade but I think, by the time that happens the cpu will probably be dead anyway.