9900k for that price wouldn't be my pick.
The 10700ka on the other hand is newer, a bit faster, runs much cooler, is cheaper in this case, and is on a much more modern platform.
9900k does have the advantage of cheaper motherboards. Z390 can be had for as little as $100 anymore, whereas Z490 start at like $150. Honestly, I wouldn't use the cheapest Z series available for either chip due to high power draw for both chips.
The 10700ka isn't a half bad deal. Its what, $50 more than a 3700x and for games it is 15% faster ish, and can overclock nicely.
However, I still don't see a use for the 10700k in general. The cheaper 3700x being way better for productivity, so it shouldn't be bought for productivity. It shouldn't be bought for strictly gaming either since the much cheaper i5 10600k is nearly identical in games when overclocked.