I think all the questions about 'how is it possible that just consistently placed 1/4 notes can be swung' are certainly valid. Here are a few of my thoughts in an attempt to think about it in some more concrete terms:
Not sure on the history of the word and semantics of 'swing' in jazz, but clearly lots of us associate it with that "swung" 1/8 note ... the 2nd note in a triplet subdivision ... the 'a' in Spang-a-lang, etc. I'm not saying that association is right or wrong. These "swung" note are certainly characteristic of much jazz, but it is the 1/4 note that is swinging.
Consider what a swing does, as in a playground. It goes back and forth, swinging similarly to a pendulum. There is not necessarily a jalopy skipping triplet-esque feel to it. It swoops forward in time and provides a strong cadence for the person on the swing, and is also sensitive to changes that person may make. Think about the movement of people's hips when they are dancing to swing music. They are swinging back and forth to the 1/4 note. Again, there is no definitive skip movement in their motion, but rather a smooth path to get from point A to point B. The "swung" 1/8ths provide a sense of propulsion and help express the flow of time in an interesting way, but the time is swinging right along, in consistent intervals thanks to the 1/4 notes.
The subtle command of 1/4 note phrasing and dynamics like what Push Pull mentioned certainly contributes to the distinction between how basic 1/4 notes can be played in a slightly different way in jazz (where the downbeat is de-emphasized among other things) than how they often get sounded in a 1/4 note rock context.
Also consider the rest of what is going on in a song beyond just the drums. If a drummer truly does nothing but play well spaced consistent 1/4 notes on the ride throughout a song then it is leaving room for the other musicians to phrase their "swung" notes over a comfortable temporal template. Similarly, a drummer playing alone could play just 1/4 notes on the ride, then insert one "swung" eighth, and then continue to 1/4 notes for several minutes and that one swung note alone can remain implied in the remaining time flow as long as the 1/4 notes keep feeling good and falling in their right place.
To paraphrase someone else, "Time was doing just fine before you came along and starting playing drums so be careful if you're going to cut it up into beats". Good 1/4 notes should be transparent when needed, flexible on the fly, and otherwise support all the other subdivisions that only can exist in reference to something consistent. And in jazz they are expressed mostly on a cymbal, as opposed to be grounded via the bass and snare drum as in rock.
But first and foremost I think is the point that drummers should be focusing on making the quarter note feel good before anything else. Sure, we are often phrasing each pulse into triplets (or other subdivisions) but those triplets alone don't make for swing IMO. If you're playing all sorts of other notes in between it doesn't matter if its not in reference to the swinging propulsion of well played 1/4 notes.
y’all have a good evening!
