So, there are so many actual issues here I'm not even sure where to start. No offense to anybody, this is just my take on things, especially you Ralson. We seemingly have some differences of opinion on some things and that's ok, but here's mine.
One, it's a pretty poor quality power supply. Jon Gerow (Jonny Guru) said it was absolutely one of the worst power supplies he'd seen come out the year that Seasonic started using RSY, or something to that effect. I believe there WAS towards the end of the Jonnyguru website a review of it, which was horrible, or at least an in depth discussion regarding the teardown, and the consensus also was that it was extremely poor quality. Maybe the worst thing Seasonic has ever sold with it's name on the label. Worse even than some of their "OEM" style power supplies. Definitely not a "Seasonic" quality level unit like you'd see on their in house designs. Definitely not a unit I'd ever recommend anybody using with any discrete graphics card.
Second, unlike Ralston, I would not recommend using System resource monitor for anything requiring accuracy. System resource monitor has long been flawed and from what I've seen it's gotten no better recently. Task monitor, somewhat better, but overall not the best choice for what you want to target and be looking at. In a pinch it could work, but truthfully your Ryzen master is probably already the much better choice for monitoring anything related to the CPU, but for an overall easily digested hardware monitoring utility I'd highly recommend using HWinfo. Just download and install it, then run it and choose "Sensors only" and uncheck the box next to "Summary", which is basically useless. And don't confuse it with HWmonitor or Open hardware monitor, which have historically not been as accurate as HWinfo and have in fact had some serious issues with misreporting of specific sensors at times. The rest of his advice is pretty spot on though, particularly using Task manager to determine exactly what is using the available resources.
If you've installed ANY of the commonly problematic motherboard utilities/software available on the motherboard manufacturer websites, like Command center or MSI gaming app, after doing a clean install of Windows, and have the same problems, there's a good chance one of those or something similar could be to blame.
MORE importantly, idle temperatures are basically irrelevant in most cases ALTHOUGH, yours is unusually high. My guess is you have a stock CPU cooler that is either not installed properly, has come loose in some way including potentially one of the two plastic brackets that pinches the motherboard in between themselves and the backplate, not to mention a case with extremely limited airflow. The first thing I'd recommend you do is take off the side panel and see if your temperatures drop and if there is any change in performance after doing so. I'm betting there will be.
Take a look in the BIOS and tell us what the ACTUAL installed BIOS version currently is. Often people think they have the latest version, and don't. In some cases, they aren't even close. Furthermore, if you've updated the BIOS at some point it's very possible that you've lost many or all of your custom settings. Your memory might no longer actually be running at it's XMP/AMP/A-XMP profile configuration. Seems every time I update a BIOS, and it's been this way forever, even recently (Despite many motherboard manufacturers claiming "this setting will survive BIOS updating", which it doesn't) I have to reconfigure CPU cooler and case fan curves, XMP profiles and other critical BIOS settings. I'd double check this and also use HWinfo or CPU-Z to see what the memory is actually running at. Simply dropping off from a fast XMP profile speed down to the default 2133mhz can have a drastic effect on system performance.
Additionally, if you have PBO enabled in the BIOS with nothing more than the stock cooler installed, that's often been a prescription for trouble as well. It would be a really good idea to get a better cooler no matter what else you do or what the problem turns out to be. And we can offer you specific recommendations on what models out there are actually "better", because there are a bucket load of them that are not.
First though, take off the side panel and run it that way to see if it makes any difference in temps and performance. First.