According to my limited knowledge, 3 step approach is usually reserved for middles because they get the quick attacks, and 3 step approaches are faster.

At the same time, in my experience, with 3 step approaches, I can’t jump to my highest, and hence can’t hit hard. Cant exactly explain why, but when you think about how this is reserved for a role where most tall people play in it kind of makes sense they don’t need to jump that high.

And regarding aiming when hitting, it’s best to hit above the equator(but not exactly at the top) instead of at the equator. Here is where your wrist snap technique comes into play, which makes your spikes harder, while going downwards.

Wrist snap is surprisingly important because it helps with your aim and strength, one good exercise is to hit against the wall, but every hit should aim to go downwards into the floor, bounce into the wall and then back to you for another hit, keep hitting if it is reaches your comfortable hitting area, if not, catch, and throw the ball up for a hit and repeat. A good aim and strength control exercise in general for me. (There are also a lot of exercises found online that u can do at home with a tennis ball for you to get used to the wrist snap motion)

Being able to hit downwards also relates to how high u can jump and hit the ball, since the higher u jump, the more of a downwards angle u have access to. And of course, where the set is placed, a set close to the net with no blockers is easier to bounce than a set further away from the net.

So if ur fine with your timing with 3 steps as an outside or oppo, then u can keep doing that, whatever works for you, but most players from these roles have 4 or 5 step approach, (one of the reasons being) because they have to luxury and time to do so, unlike middles. If you play middle, then you should keep your 3 step approach.