I'm never doing some weird stuff that is not near what I do in my game.
Like I don't play a lot of closed guard. If I watch a video about a triangle choke from there, Everything will go wrong. I'm not good in that position, it's not natural for me to be there, I don't have the right grips, I'm not efficient AND I'm trying a new move. Plus the fact that I won't go naturally into the position, that I have to think about it...
But I've been playing with Half butterfly guard for 5 years, I'm doing it all the time, If I watch a video about a new X guard entry or a tweek for a sweep, I can do it right away because I'm good in that position and I'm gonna have a shitload of occasions to try it.
The other thing is that a lot of stuff is more about the setups and getting into a position. Let's say the 4X4 mount video by Danaher
The whole point is to get to mount with the other gu's arm trap over his head. The finishes are pretty basic, it's the hand fighting game that is important and that starts early in the move. What's the point of drilling the actual technique that is the Mounted triangle when all the hard work is on getting into position to do it.
Same thing with the back attack system, you need to be good at all the grip fighting, because doing the actuel finishes are not that new, it's the way of getting there that you need to get good at
Posistionnal sparring would be the best most of the time, way better than just rolling. But drilling as limits