My YouTube process must be very corner case. I usually keep an eye on subscriptions during the day and add the videos I want to watch to watch later and then order them a special way. House and trailers first, entertainment, fitness and then music. I have a separate watch later for the gym that I curate in a similar order for long treadmill runs. And that gets downloaded to the phone.
I do this every day. YouTube’s changing interface designs usually make this harder and harder.
Being able to order by channel groups would actually help this but I usually watch via AppleTV app in the evening.
Apparently very few people use watch later and order intentionally. Just two actions to corner case myself.