You need to post your friend's Computer information: INFORMATION REQUIRED WHEN POSTING A QUESTION
From the first image, you seemed to be running on Windows 10 with a Nvida GTX GPU card.
Need to know the Make & Model of your Motherboard including BIOS version, GPU, and RAM Memory (part number) installed.
Also you will get better assistance if you post your question at this AMD Forum: Drivers & Software
Tested VR Chat on the Ryzen 5 1600, Ryzen 5 2600X and Threadripper 1950X on Windows 10 (1809 Build 17763.55), in both Desktop and VR Mode (WMR).
I used and RX 580, GTX 1070, RX VEGA 56 and RTX 2080... all of them were sitting at the 90FPS Maximum (most of the time) with minor dips based upon the Avatars (typically with people loading in / out).
I tested in the VR Home, PUG Pub, Stand Up Café and Nightclub (the 4 Standard Popular Places)., with basically the same results.
As such, there doesn't appear (at least to me) to be any issues with the Ryzen processors and VR Chat.
As a further note I did test on both a B350 (Asus Prime Plus) and X470 (Asus Prime Pro)., both with the Latest BIOS … it's entirely possible that compatibility / issues can arise with other manufacturers (as unlike the Fusion Media Chipset., the 300-Series and 400-Series are not created equally; and the sooner AMD stop using Asmedia for their Chipsets and get back to making their own the better) but that would more likely cause system-wide issues.
Now from what I can tell from the provided images; your friend is using a R5 2600 (Stock) / 8GB SRAM / GTX 1060 although I'm not sure 3/6GB as he doesn't show; this could make a difference.
The ONLY element that is even remotely under-load is the Memory., as it's almost 80% Utilised.
Now it could be Drivers causing the issues., or an Anti-Virus Program (Bulldog for example has been causing issues in various games, such-as Overwatch and Fortnite)., or another 3rd Party Application.
I don't use anything in regards to 3rd Party beyond Logitech G (for my mouse) as well as the usual Adobe Creative Cloud and Autodesk Access; which none of those are causing any issues with VRChat Performance.
Keep in mind upgrading a Platform (i.e. AM3+ to AM4) isn't simply a Processor Swap; as it's different Memory and Motherboard as well., these are important to match and chose well. I don't have a B450 (as they weren't available when I last purchased new Hardware for QA/Bug Testing), so maybe it could be such with an immature BIOS., but it's doubtful.
You need to provide MORE information.