“Why is it suggested to do the explosive power building jumps and throws before the main lift?”
To make this simple, because it “turns on” your body and gets you ready to lift heavy, strong and explosively.
“But if someone didn’t care about explosiveness and only cared about their lifting numbers, would it be better for them to lift then jump/throw?”
This is like saying “Well mobility and warming up doesn’t make me stronger…” Well not directly but in the long run it will. But the jumps/throws DO make a huge difference in getting stronger. Even the same day.
Doing 15-20 jumps or throws will NOT fatigue you before lift - if it does, it means one is horribly out of shape. Disgustingly out of shape. At the end of the day, you don’t have to do anything you don’t want. It’s just been my experience that a strong, explosive, mobile, well conditioned person is far superior physically to someone who just lifts weights. It’s about the TOTAL program, not just chasing numbers. Just like life isn’t just about work or whatever - when there is balance, there is a better life. Or at least it puts you in a better position.
This is why we have NOV challenges that challenge both strength and conditioning - and why the conditioning we do now in my gym is so vastly different than what most preach. We have evolved! We are blurring lines.