We are taught that with 8 cards between the two hands and with the AKJx or KJxx (opposite Axxx) in one hand we should finesse but with Nine cards we should go for the drop of the Queen.
With 8 cards in the two hands, without any further information, the finesse is 50%. Suprisingly with nine cards it only reduces to about 46% so there is not a lot in it.

So consider "not always"
When you cannot afford a loser in the suit and with nothing else to go on follow the maxim.
But if you can afford a loser there may be other things to think about, particularly at Teams, Chicago or Rubber but it can also apply at pairs.
For example, if a losing finesse would land in the hand of the opponent who can give their partner a ruff that you can't afford, then with eight cards you might have to play for a "drop" by playing the Ace and King then a small one to the Jack. If the finesse would have lost, the dangerous opponent can't give his partner a ruff, because he can't have any more trumps left
Another situation is where you can count the right number of tricks only by cross ruffing.

A simple example might be
You are in Four Spades

Dummy   ♠ 9876 ♥ A54 ♦ A ♣ 97542
Declarer ♠AKJ3 ♥ KQ3 ♦ 8764 ♣ A8
With this particular holding on, reasonable breaks, you can make 10 tricks on any lead by cashing winners and cross ruffing.
If you take a losing finesse and the opponent with the Queen returns a trump you can only make 9 tricks.

One point that might help you to decide whether to "risk" the finesse and perhaps make 11 tricks or go off if it is wrong (not in the above example) is how likely is it that most of the room will be in the game contract. If the answer is very few then play safe but if probably everybody then you decide whether to go with the field or take a risk if you badly need tops.

Lacking any further information, this maxim suggests that the best odds are to finesse when holding a total of eight cards in the suit, and don't finesse but play the two top cards to cause the queen to be "dropped" if nine cards are held (about 54%). With nine cards, because the difference in percentages is so close (54 to 46) expert players will often try to gain further information to try to deduce which hand is likely to hold the queen, before choosing their play
e.g If in No trumps, play on other suits first to get an idea of the distribution if you can.