First of all, welcome to Zorin OS 16! And it looks like you have been learning Linux for awhile, and I think that is pretty stellar.
There is most certainly a learning curve when it comes to Kdenlive, but it is the best video editor for Linux, you will not find better, when it comes to features supplied, and for file support. Another video editor that is good, just not as good, is Openshot, but you said you've tried that and didn't like it.
The thing with Openshot, is that its very basic, and has a pretty GUI, and doesn't have the steep learning curve that Kdenlive has.
Have you tried Shotcut?
Its not as powerful as Kdenlive, but more powerful then Openshot, but it comes with some good features, and this would be closer to a comparison with Windows Movie Maker, which may also match up a bit with Filmora X for you?
Vivia is another suggestion...
Its a basic video editor that shouldn't have a super steep learning curve, and should also be as easy to use as Windows Movie Maker, or Filmora.
The thing with video editors, is that by their very nature, they are a bit complex, there is no such thing as a perfect solution for everyone. Thats why they have the basic versions, as well as professional versions of software.
For example, if you were asking me from the perspective of a professional doing video editing, I would have recommended Kdenlive
Or I would have recommended Lightworks
But for basic video editing with less of a learning curve, the first 3-options that I have shared, should hopefully fit the bill nicely. And Harvey is correct, I do both 1080P and 4K video rendering.
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