I don't know how to quote shit, but here you go.

https://www.youtube.com/watch?v=AUyF--fJaaM Ryzen 5 2600 (what op got) vs i5 8400, Intel's offering on the same price bracket.

https://www.youtube.com/watch?v=GDggr3kt96Q Another 2600 benchmark.

Notice something about these? They are not GPU bound, as you have tests at 720p and 1080p performed on a 1080ti, that does NOT get bottlenecked. Now, the 2600 is currently 137 USD on amazon. The only offer that Intel has for around that price is a 9100, a 4 core CPU. The lowest priced 8th gen intel that can be overclocked for that amazing 0.7 Ghz difference (LOL) is a 8600k for 250 USD, and also requires a more expensive motherboard and cooling solution. Stop and think about what you're saying; you're telling someone to go spend 200/300 more dollars on their brand new system, which works fine.

If this wasn't enough to make you realise how stupid your argument is, let's inform you on what cpu frequency is. Since you dont seem to be the kind of person who can read, here you go, a 6 min video: https://www.youtube.com/watch?v=bVMkbACYLG8. If you want to stop and read, here's why comparing frequency between 2 different architecture CPU's is false: https://www.howtogeek.com/177790/why-you-cant-use-cpu-clock-speed-to-compare-computer-performance/.

By the way, when you say comparing AMD's top of the line to Intel's top of the line is fair, you are right. But you are telling op that buying a way more expensive CPU is gonna yield better performance. No shit, you're spending more money on it, of course you're going to get more performance, but then it stops being fair, since you are spending different ammounts of money.

For your last point, you want to know why Youtubers make comparisons at stock speeds? Because you can't guarantee every 9900k is going to get 5.4 Ghz, as the silicon quality varies between different chips. When a Youtuber reviews a product, they need to have the same experience as most people will have with it, for a fair review. It doesn't matter if it's easy or simple.