What I have found as I’ve moved into bigger, faster, and more slippery machines is that in a jet on approach, a small change in pitch causes a moderate change in flight path but a only a small change in speed, therefore pitching for speed doesn’t work very well. Point it where you want it to go and adjust thrust for speed makes the most sense to me! On the other hand, in a C172 a small change in pitch only causes a small change in flight path and causes a moderate change in speed, so pitching for speed in something slow and draggy works if you prefer to think of it like that. The truth is, as said up-thread, it is the combination of pitch and thrust that gives you your performance and if you change one then you will probably have to change the other as well.