My situation: I also have "random" crashes on RStudio startups. When it occurs, the situation is quite similar to yours. I've tried things like "Resetting a user's state on RStudio Desktop", however, I couldn't completely solve or reproduce the problem.
My recent finding: I found that RStudio is likely to crash after I update the preview versions, because I usually go with the portable version for Windows. Each time I unzipped the latest version in a different directory, then the Windows Firewall tries to block the R session executable file.

I think the firewall settings have something to do with the crashes, so please check the firewall setting after update, and especially try the new Terminal tab after successful startups. If the "Windows Security Alert" pops out, click Allow access, and I think this would increase the chance of sucessful startups in future.
Hope this helps.