Seems like this is derived from a dissatisfaction with maintenance, but all I'm seeing is that they're maintaining things just fine. Yes, there are a lot of open PRs, but there are also quite a few merged, reviewed, and closed PRs. While I do support forks in the spirit of FOSS, I disagree that YT-dl is being poorly maintained and find that it continues to work well for my needs.
To the person who started the fork, what happened when you inquired about the apparent problem via email?