The only tool in Linux that's really decent at editing video isn't even a video editing tool. It's Blender.
For the past few years I've just used Resolve in Windows. I'd be excited to try Shortcut and see if it handled better.
Video editing is a though medium though, even if you're just calling ffmpeg a lot. It's worth watching the Vimeo talk and video encoding and how a lot of cameras and cellphone encoders are so crappy they can change framerates on every frame.