Coming from an Intel machine it might seem high but it’s absolutely in the expected behaviour for Ryzen to run at those temperatures while idling.
If you want to make it run cooler (which might even make your benchmark scores a bit better due to Ryzen’s boost by temperature algorithm) is to just apply a negative voltage offset.
Just make sure to check with benchmarks if you’re undervolting too much and you’re losing performance.
Usually Ryzen “likes” -0.1V max so you might wanna start low and work your way up to -0.1V.
I didn’t try it but, if you don’t feel like doing work manually, you can try 1usmus clock tuner for Ryzen (not out yet) which can apply overclocks and slight undervolts while automatically doing testing and validation of the applied settings.
Another suggestion I have is try to lean more on RAM tuning for Ryzen. That will help quite a lot to get better performance while not increasing the CPU heat output.
Keep in mind that the sweetspot for RAM clocks on daily usage for Ryzen is 3600 that keeps IF clocks and memory clocks rateo 1:1.
So, if you’re willing to spend some time RAM tuning, there’s also 1usmus RAM calculator for Ryzen + you’ll need programs like TM5 + anta777 extreme config to give your RAM a thorough testing.
That’s all I gathered since I built my first Ryzen system a couple months ago. Surely there are more knowledgeable people around to help you out, but I hope my inputs are a decent start.
A post that might answer some more of your questions regarding idle temps and voltage.