People really get confused when they see 50% reduction and exactly the same as X and think they’ll just crank down the bitrate and be good. As others have said you really should try a few options although instead of bitrate you could try using crf values and find what works on your setup.
Also while screenshots can help, it really is something you should look at in motion. Sometimes you can think ‘this looks horrible’ but in motion it’s fine and you never see it. But it also works the other way too.
There’s a science and an art to getting good encodes. Hell even the encoders update and update little things behind the scenes that can effect the outcome as well.
Glad you were able to back up your favorites, sounds like it was a cool channel. Sad to hear about stuff like this after it was gone.