Hyperthreading is a method where 2 threads can be made to share a single core bandwidth. But this is not a true 50/50 thing. If a code string takes up 60% of the bandwidth, the cpu gets to decide if it makes the other simultaneously pushed thread wait its turn, or if it sneaks in a code string that's less than 40% bandwidth. Because of that discrepancy, you'll see hyperthreading only get @1.5x more ability, not 2x as would be assumed.
This is what makes the 8th gen i5's with 6 cores so strong, equalling older i7 performance on games that use more than 4 threads, you get a 6core cpu vrs a 4core cpu x1.5 and the 8400 has higher IPC than a 3rd gen i7.
The Ryzen cpus have IPC that's comparable to at least Haswell to almost Skylake, so are just behind the Intels on performance, but coupled with high speed ram such as 3200 or better, can get @20% better IPC, putting them at at least Skylake and knocking on CoffeeLake back door. Ryzens are also unlocked and hyperthread capable, so for a bit less cash, you get a 6core cpu that's equivalent to the 8400,but also has hyperthreading to bump that to 12 threads, which is great for gaming and streaming or production software. A Ryzen 1700 can WinZip a large file about twice as fast as an i7-8700k.
So each has its strengths and drawbacks, either can perform better, depending on the game, the software, the setup.
Here's what many do not think about, being concerned solely on performance. A standard 1080p monitor is 60Hz. 1Hz = 1fps. The maximum amount of fps that you can get on that monitor is 60, no matter what the counter says it is. So there's exactly no difference if a Ryzen 5 puts out 200fps or an i7-8700k puts out 300fps, you get 60. The only difference lies in minimum fps. If the minimums on the Ryzen drop below 60, you've a good chance of seeing that. The i7, being the stronger cpu, might not drop below 60, so would be the better cpu. But if all minimums are above 60, there's no difference at all to you.
The only time maximum fps are of any concern is on 120-144Hz monitors. And that's only saying if you only get a max of 90fps on a 144Hz monitor, it's time to drop some settings or get a stronger cpu.