The 9900K runs and runs, depending on what else you have installed.

For me (i9-9900K, RTX2080TI, Z390 motherboard, 32 GB RAM, 1.5 TB SSD from Samsung and a 2 TB HDD) every game runs in 4K without problems. Cutting and resaving videos is done within a few minutes.

You could stick with 6700k unless you can use the more cores (video editing) but then right. You have to change motherboards so AMD Matisse is the better choice these days.