I just realized now that I forgot to post my build, so here it is: https://pcpartpicker.com/list/4DRt2m
The only difference between my current build and my new build is that I'll be switching to the ASUS motherboard. I'll also switch between a 5700X and a 5800X to see which works better. I heard they're pretty much identical normally, though I don't know about PBO. The 5800X apparently runs hotter though which I've observed from my testing as well.
This is the motherboard I'm currently using. I thought that this would be sufficient to run well with all of my parts, but I'm having microstuttering and stuttering issues with a 100% new build I built a month ago. I thought I might as well upgrade to a more high-end X570 board with integrated Wi-Fi to see if that makes a difference at all. Hopefully, this fixes my issues.
As for a wired connection, my modem is stuck downstairs since it was plugged into... somewhere outside. My router is also stuck there as well. I haven't looked into ways to get a wireless router or something of the sort, but maybe I should. What can I buy to use a wired connection if I can't move my main router? Would an Ethernet connection improve stuttering and microstuttering compared to a Wi-Fi connection? I don't see how that would affect anything other than online games, but I'm very desperate at this point and I'm trying everything. I tried to remove my Wi-Fi card entirely, and this hasn't affected performance at all; thus, I doubt an Ethernet connection would help in that regard. Still, it'll definitely be far faster and more stable, so I'll look into that.
Here are the links for the other ATX and ITX, thanks to u/MetaJesus