This is the opinion of a student of Lubomyr Melnyk's "continuous music".
No, you should not lift a finger with the stated goal of hitting a key (not really, not intentionally). You should not strike, attack. If you have sufficient finger strength, you can press calmly into the keys, taking them all the way down to the end of their stroke, without effort; then you can create any volume or touch that you wish to. The piano should yield to you, the notes falling away with ease. If it does not yet, then you are playing a piece too difficult for your hand to manage.
Of course, the fingers are in motion and if a finger is deep into one key and is called to play another, it must lift off from the old and land on the new, but a raised, curled talon in the air coming down to slam a key.. for the sake of volume.. this is unnatural for the hand; tense; forced. Rather, it can move a small, imperceptible, unconscious distance, within the confines of the hopefully relaxed hand surrounding it: or if a greater movement is needed it can have the wrist fluidly carry it and the rest of the hopefully still relaxed, but strong, hand to where it needs to be. Why expend tremendous (and conscious) effort in raising a finger away from where it must be? In the raising and the curling, you typically obstruct the muscles and contort even what is happening in the palm of the hand. If you maintain this for ten minutes, twenty minutes, an hour, in motion, it is not good for you at all. Maybe you can even do it without noticeably hurting (depends on the piece), but it limits fluidity and relaxation.
The sensation of playing with all fingers at rest on, or pressing in, the keys - rather than being in the air - is a wonderful one. Not too easy to achieve, I am guilty of raising them slightly from time to time, but I experience very obvious tension when I do that! It is a problem. Usually, it is a symptom of playing faster than I am really able to (of forcing the speed), and it happens much less often these days.
Raising the fingers this way can be a good way to build strength, in the weak fifth fingers especially, but I would strongly caution against doing it in the fluid motion of a piece (and if the piece somehow demands it as a matter of course, perhaps by having obscene arrays of jumping octaves, I would criticise the piece as - while possibly quite beautiful, who knows - unnatural for the hand). Tapping on a table, I still raise my fifth finger quite high and bring it down sharply (all other fingers static) for the sake of exercise, but I wouldn't dream of doing so during a piece. At least, if I recorded myself and found out that I was doing that, I would be quite annoyed and would seek to change it.
It is quite possible to play with volume and strength, flowing from the entire body, with fingers hardly ever elevated from the keys at all - and certainly never 'in the air'. If a piece is within your grasp, then the depth of touch and volume can be accessed just from the way you perceive the notes and lean into them. Hearing the music as it is played is very helpful for that. Accentuation can emerge unconsciously or consciously. Having a close physical (and mental) connection with the piano goes a long, long way.