2080 Ti is better than 2080 for gaming, difference is game dependant but its from 5 to 15% faster.
But i9 10900k is way better for work 10 cores (20 threads) vs i7 9700F 8 cores (8 threads).
If it was up to me i'd go for the better CPU, but i don't game that much.
Maybe the 2 CPU in terms of Gaming will be pretty close.