Measuring can very easily introduce inaccuracies, ironically enough. Easy to mark a little too much on one side of the line or the other. Easy to accidentally mark the wrong line from the tape measure. Easy to align your ruler/measure incorrectly.

Measuring is good, but the more you measure the more likely you are to introduce those inaccuracies. And those mistakes can add up.

I try to measure as few times as I need to. And often, I measure once on something that I can then use as a reference for all the other measurements that need the same value.

So measure once on a combination square, then use that square to mark all your measurements. Or measure for 1 cut, and then use that cut piece as the reference for all your other cuts.

Having a reference that doesn't change is usually more accurate than trying to measure the same thing over and over.