Constant crashes, Rendering device lost

Have you checked the known issues thread pinned at the top?

Maybe it’s this:

https://us.forums.blizzard.com/en/overwatch/t/known-technical-support-issues-updated-april-12-2020/25/25?u=nicole-1893

There is also a known issue with Ryzen processors:

Also, small tip: Overwatch runs best on dual-channel RAM, same speed/size.