Why do quarks and antiquarks tend to bond in groups with quark number a multiple of 3?
I understand why they might in bond in groups of three to create a net charge of zero (i.e. neutrons), but I don't understand why they form protons and not, for example, commonly form in groups of four. I have done background research on this question, and did not find any information. The wikipedia article on baryons (https://en.wikipedia.org/wiki/Baryon) was not helpful either.
To summarize, why are mesons and baryons more common than other hadrons?