If your primary use is Gaming and then you might go into streaming 9900K is a better CPU. For any task that does not include rendering 9900K at 5GHz beats Ryzen. Even if you use Adobe Premiere, 9900K is still better because it uses iGPU and gives you much smoother user experience.
If you want to go into the world of streaming I recommend you to visit
EposVox and watch, pretty much, all of his videos. He has 5+ hours long in-depth tutorial for OBS. It is amazing how you can make your streams look nice without using server-grade gear to render them. The guy is brilliant.
If you play games and enjoy playing games 9900K is a better CPU. Even GamersNexus says that in the conclusion of the Ryzen review. If you do production stuff and occasionally play games then Ryzen might be for you depending on your workload.
Go for 9900K. You will enjoy your games at high FPS and if you start streaming with EposVox's channel you will master OBS and your streams will look beautiful without dropped frames, and taxing to your framerate. 9900K is a beast of a CPU. Don't let that shouting about how Ryzen is better than Intel at "everything else" cloud your judgment. Everything else requires more cores. So the one who has more cores wins. The thing is you are not doing everything else. You are doing stuff that Intel is much better for.
Example. I do Music production, Gaming and Photo editing on my computer. I followed everything about Ryzen. I wanted to build Ryzen 3000 rig. My 4790K is starting to be not enough umf for what I do. Ryzen has more PCIe lanes, it even has Thunderbolt on ASRock boards. Ryzen 3900X looked like a perfect CPU for me. But sadly it isn't. For those main things I do Intel is still better. So come fall you will see my new 9900K rig, or I might hold on a little bit longer and go with X299 Cascade Lake-X. Don't get me wrong Ryzen 3000 are beautiful CPUs. I like them a lot. But they are not for me.
I hope this helps you decide.