Exactly.And of course everyone forgets to mention that Ryzen often has higher min FPS despite having lower AVG fps. But hey let's not let that complicate a good discussion on why Ryzen is an "awful gaming CPU".
Regardless, to get back on topic . . . OP should just get the 8700k, it's what's hot today. Okay?
If I was purchasing I'd probably get the 1600x, cheaper, good enough, has better upgrade options for the future, and I wouldn't feel dirty about purchasing it. But honestly if someone asked me to recommend one of the 3 as a gaming CPU, it would obviously be the 8700.
The 7700 is capped in gaming, it will never do any better than it is right now and debatably struggle quicker than either of the other two as time goes on. The 1600x is a good chip, this type of it's system is it's sweet spot. But it doesn't have the oomph to compete with a similarly core'd Intel alternative in the long run. It's singular advantage is more forward facing, which is getting the 1600x to buy a Zen+ next year or a Zen 2 in '19. The 8700 has everything the 1600x has, clocks higher, does everything faster. It's the obvious king here.