You might encounter the odd game that is, in some areas, CPU limited. Maybe a given title wants more threads/cores, or maybe another really wants some extra frequency.
But in general it shouldn't be a significant issue, not one that would generally prevent you from seeing a substantial performance uplift.
Hardware Unboxed have a graph showing relative difference between an AMD 3950X and an i9 10900k at 4k. Not quite the same setup as your but the point is that such differences as there are between those CPUs get eliminated at 4k even with the 3080.
Oh, and actually Tom's Hardware have an article exploring 4k performance of the 3080 paired with various CPUs:
Breaking the bottleneck
The upshot of which appears to be that your CPU is fine. At least far as the games they tested