30mph does not require anywhere near 1000w, it's more like 350-400w on flat ground depending on the riders position and size. I'm a former amateur racer. I've done 30mph steady state for a mile on flat ground without a draft before. That's a 2 minute mile and there is no way on earth I could ever do 2 minutes @ 1000w. 1000w is more like a 5s sprint for an amateur, you would put that power out in a burst to accelerate and probably end up doing about 34-35mph on flat assuming no draft. Pros are probably more like 1500w. 30mph is nothing. I probably exceed 30mph every time I get on my bicycle if I'm riding for exercise as opposed to commuting. Almost no race goes on where speeds don't hit 40mph, and 50-60mph is not rare.
Rolling resistance is not drivetrain resistance. Most of rolling resistance is tire resistance. It doesn't scale up at the same rate as aerodynamic drag.
Chain resistance is much smaller than tire resistance. It does go up with power but not really with speed directly because you shift.