I'd always recommend Shotcut. It's stable, easy to use and actively improving. People working on it look like pros.
I donated to Pitivi a while ago. They've been aiming for release 1.0 for a few years now.
I tried Pitivi and Kdenlive a couple of years ago and found them both unstable. Saving and loading projects were not reliable. They'd suddenly quit while working with video.
Blender and Shotcut were fine, but Blender is a bit more complex.