> Compatibility is an illusion. Most people tend to date until they have an idea of "what they don't want". Once they know and they find someone who checks the boxes, they settle down.

I don't see how this suggests compatibility is an illusion. You just described another way of finding someone who is compatible. Personally I already had a mental checklist of everything I wanted out of a relationship, no dating around was necessary to know those things. Just basic introspection. I ended up marrying my second girlfriend and I would say the relationship is 100% perfect.