Let me pick apart the standard argument "only if you need 16 cores" (or whatever core count) ... but if we look at the current existing lineup ... what if you only need 8 cores? Under that statement th e9900k seems like the best pick. The 9900k is great if you only need
4-6 cores ... but if you need to max out all 8 cores for multi tasking / multi-threaded work, the the 3800x still makes equal or more sense than the 9900k.
But if all you do is "game" or web browse or whatever, that basically only needs
2-6 cores ... then the 9900k works great (but a high price). But if you
really need to use all 8 cores, then the 3800x is s better performer, and additionally the 9900k tends to lose it's all core boost after a couple minutes of load, unless you've made bios provisions or manual OC, in which you are going to have a fair bit of heat to contend with.
https://www.overclock3d.net/gfx/articles/2019/08/29121100864l.jpg
So the blanket "only if you need X cores" isn't quite what it seems. if one puts some thought into it. Just an observation, wasn't picking on your post.