Certainly, they track the quantity of each suit and the high value cards, but I'm curious if good bridge players also remember, say, whether someone ducked the ace using a 7 of spades vs a 6 of spades.
Obviously, this answer depends on your meaning of the word 'good'. However, I consider myself a good bridge player, and find myself not often needing to track the nuanced difference between 6 and 7. Most hands are not decided in table play, but in the bidding, and most are determined by leading, the high cards and the trump suit. There are situations where I would need to track a spade 6 or 7, but often that's when I've got a hole that I need my partner to fill, or attempt a finesse. In such situations, I'm looking specifically for those problem cards, so I don't need to track every card.
There are unforeseen situations where tracking every card could give a slight edge, but those happen so infrequently that it won't make much of a difference in one's overall 'goodness'.
Incidentally, there are mnemonic tricks that allow one to easily track all cards, I just find it not worth the effort in standard bridge.
While it is true that the play is largely determined by information gleaned from bidding, high cards, leading, and the trump suit, there is one aspect of bridge where precisely tracking every card is very helpful: defensive signaling. As Wikipedia describes, "partners defending against a contract may play particular cards in a manner which gives a signal or coded meaning to guide their subsequent card play; also referred to as carding." Obviously these signals will only work if the partners are tracking cards precisely, including their sequence. And this goes for the offense too so they can gain information as to where cards are placed among the defenders.
The most common example where remembering a low discard is vital is the high low signal indicating a doubleton, and thus a desire for partner to lead back that suit a third time if trumps have not yet been completely pulled. I've typically played that this can be with a first card followed by a second lower card, even a 3-2.
Another common example is leading the fourth highest card from longest and strongest when defending a no trump contract. In this case, it is helpful to subsequently remember every card played in that suit as this often makes it possible to infer exactly which cards are held by the opponents in this suit.
One could reasonably argue that you can get by just remembering the first card played by the first and third seats (in addition to tracking high cards and trumps), and that will probably get you by for the defensive signals typically applied by beginning to intermediate players.
However, you asked if good players memorize all cards. I'm not sure how good you mean but at the higher levels of play many forms of defensive signaling are used. The more defensive signals you use, the more it requires remembering not only exactly which cards have already been played, but the exact sequence in which they were played.
My guess is that SOME good players will memorize individual cards (because they have a "knack" for it. But many, probably will NOT.
I'm not a "good" player, but know that it is important to size up the hand. That means looking out for opposing honors, and also for missing trumps. Tn this way, I focus on maybe 10 of the 26 opposing cards. Sometimes more (13-15), if there is a critical side suit.
It gets exponentially harder at each step; going from tracking 7 cards to 13, and 13 to 26 (that is, quadrupling difficulty for each numerical doubling). Most good players take the first steps (up to 13). Some go all the way to 26.
In his autobiography, Lee Iacocca told the story of how his boss, Robert McNamara was shown a 750 page presentation, and on page 724, he said, "That contradicts something you said on page nine." That kind of skill does exist, but it's pretty rare. Iacocca himself probably didn't have it.
This boils down to issues of active thinking and observation. Good players weigh expectation against actuality. But the tools for determining actuality are tools of observation, not memorization. (s)he looks at every card, but there is no value in memorizing them. The dire need is to determine where his tricks are coming from. The tools for this include planning, reconstructing the original four hands and determining how to play certain card combinations and analyzing the opponents' motives. By observing every card in the context of reconstructing the hands, the information such as order of play of spot cards is available if needed. But most of your useful information is gleamed from an analysis of what did not happen. Say, for example, you are defending a contract of 3N. Dummy has DAQJxx, but declarer has tackled a short suit and you are in. You know that declarer holds the DK. Your target number of tricks will be informed in part by that knowledge. THEN you recall that partner (or opponent) gave count in another suit and know that you can wait for your tricks or that you must cash out.