Threadripper, like all Ryzen, hits a hard wall at 4.1ghz. So if you want overclocking, then you may not want a threadripper. But skylake x takes a deepfreezer to keep it cool, so it hurts its potential to overclock.
You should only get either of these chips if your primary goal is video editing. If you want an editing machine that can game, then great. But neither of these chips are great gamers.
The 7900x has better single core performance than threadripper, but threadripper dominates it in multicore performance. The purpose of getting either of these chips is for multicore performance because the 7700k at a third the price beats both of these chips in single core performance.
It would be really hard for anyone to make a logical argument to choose the 7900x over threadripper when you consider the price vs performance ratio. As an Intel owner, I would definitely go with threadripper IF I needed a machine for multi threaded applications.