I think you kinda answered your own question: > P.S. I tried using Pixelmator (non-free), GIMP, OpenShot and a few more open-source editors - they don't stand

I think you kinda answered your own question: > P.S. I tried using Pixelmator (non-free), GIMP, OpenShot and a few more open-source editors - they don't stand the competition. It's really hard to do it right, and even if you do you're targeting just a single segment of the market (people who need more than iMovie but not everything that Premiere provides). I imagine more than a few people have looked into this and decided that isn't a good ROI for the amount of investment involved. Also, don't forget that Adobe (used to, anyway, not sure if they still do) has really cheap student licenses so that aspiring designers/editors/etc. get hooked on their software and carry that preference over into their professional lives. My guess is that anyone who really has a passion for this has a regular full-time job and works on something like GIMP in their free time.