The terminal and all tools that are built for it. After enabling WSL, my computer performance went down a whole lot. File permissions issues between the two systems were constant, and I typically spent more time troubleshooting things than actually doing work. I think I wouldn't mind having a Windows as a personal PC, but not as my work computer. When I'm at work I just want to get work done and not troubleshoot the operating system.
To be honest - if you don't require Adobe or Xcode, I've had great luck moving almost full-time to Fedora. I still have a Mac...but it's pretty much only for Logic Pro X.