> I sometimes wish would include "In our current model", "We now think that", or some other qualifier.
There is actually good reason to think quarks aren't fundemental. Even ignoring the empirical shortcomings of the standard model (specifically the incompatibility with General Relativity), it just doesn't "look" like a fundemental model.
Specifically, it is essentially a periodic table of elementary particles, with 3 "generations" of matter particles. Like the periodic table of the elements, this structure is highly suggestive that there is some deeper underlying structure.
I agree that we don’t know. But there is also evidence that quarks are fundamental. Based on all our measurement, they are point like particles with no internal structure or size.
There is actually good reason to think quarks aren't fundemental. Even ignoring the empirical shortcomings of the standard model (specifically the incompatibility with General Relativity), it just doesn't "look" like a fundemental model.
Specifically, it is essentially a periodic table of elementary particles, with 3 "generations" of matter particles. Like the periodic table of the elements, this structure is highly suggestive that there is some deeper underlying structure.