youtube-dl is great but if you want a GUI way to download video from YouTube and almost anywhere else, I highly recommend Downie.
It works great, it's constantly being improved, it's developed by a named, reputable developer (unlike some tools out there which seem a little "fly-by-night"), and it has some nice Mac-specific features.
There is a free trial ...
I found Unshaky on GitHub (https://github.com/aahung/Unshaky)
I've been testing it for about day and so far it has been working fabulously! During a full workday I experienced a double-keystroke only once.
Please note that you have to set it up:
I put 40ms delay for each key:
I also made an exception for the Tab and Delete keys which I regularly hit ...