Sure, quarks and leptons are maybe a high-level concept that masks a more messy underlying reality, but surely quarks and leptons are less messy than dogs? There is an arrow of progress in the development of physical theories. I don't see a reason why a perfect description should not be possible.
Even wrong theories can be useful in some contexts, Newtonian gravity for example. Take it to an extreme: say quarks aren't useful at all for science, but are a useful conceptualization pedagogically, it can still be worth.
It seems that different people often use "not wrong" to mean two different things. Some people are using the word to mean "useful as far as it's meant to be," like you. Some people, like the GP, are using it to mean "the truth." It's important to clarify what you mean when you're discussing, otherwise there's heat and not much light.
In case of physics we do not really have access to the later kind, every theory is a current best guess that might at any time turn out to be only approximately correct or under certain circumstances. General relativity is almost certainly not the truth, the universe probably has no singularities hiding behind event horizons, but does it help us to call it wrong?
There is reality and there is series of better and better mathematical models of reality and all of them are wrong in the strict sense until we eventually find the final theory but even then it is not clear that we could even recognize that we have arrived at the destination. In the end a binary characterization as right or wrong does not make too much sense for physical theories, they occupy a continuum of correctness.
I somewhat agree with you, but I think it's very important to distinguish between the two meanings, because different points on the continuum of correctness cause you to come to completely opposite conclusions about the nature of the universe. A bit of quantity leads to a totally different quality. In other words, truth and usefulness are continua, but they are two different and orthogonal continua, and going right on one may mean going left on the other.
My view of the universe is going to be totally different if Newtonian mechanics is the "truth", versus if something like quantum mechanics is the "truth." The former depicts a totally deterministic and knowable-in-principle clockwork universe, whereas the latter has randomness and ignorance that cannot be removed even in principle. Quantum mechanics may not be the whole truth, but it's certainly so different that it shows earlier approaches to be not just incomplete but totally incorrect about their fundamental assumptions, even if they can be used to make useful predictions. Quantum mechanics isn't just more useful, it's more true, whereas Newtonian mechanics might be more useful than some other theory, but actually less true in some sense.
Counterpoint: Newtonian Gravity could be considered profoundly wrong since it presupposes a structure for space and time which is fundamentally wrong. What I mean is that ontologically Newtonian Gravity is a total non-starter, implying the existence of relations which are simply totally absent in this universe.
Everything falling at a constant speed of 9 m/s takes this probably a bit too far, on Earth this will only be true for tens of milliseconds before the speed is of by a few percent. Had you said every objects accelerates with 9.81 m/s², that would be a pretty good theory of gravity on the surface of Earth, probably still the dominant theory for solving gravity related problems on Earth.
Your example reminds me more of the difference between Aristotelian and Newtonian physics. Aristotle - looking at the world around him - thought that the natural state of motion is being at rest and that it requires a force to make an object move. Newtonian physics realizes that this is not the case, that without forces objects keep moving instead of coming to rest, that Aristotle lacked a proper understanding of the role of friction.
To come back to gravity, space flight probably still heavily uses Newtonian gravity and it works, for that reason alone I would not call it wrong. Objects falling at a constant 9 m/s seems to have much less practical use and does not even get the most important characteristic of gravity - that it accelerates objects - right, so I will agree with you and call it wrong.
The difference is that the region your theory of gravity is a good model in, is not inhabited, whereas the region that Newtonian gravity is a good model in is the one where most of us spend most of our time.
