I've had versions of the Video DownloadHelper add-on for years. I'm not particularly clever with tech but Video DownloadHelper has made it easy to save videos I'd like to "keep." It also updates fairly frequently with improvements, which I appreciate. Someone is keeping their eye on this ball.

Video DownloadHelper's a favorite add-on with me, and doesn't HAVE to cost anything to use (though donations are obviously an appropriate expression of appreciation). I'm glad to give it a positive review.