What does personality even mean?

I've seen people saying that when it comes to dating, personality matters more than looks. But what does personality even mean? According to dictionary.com, it means the specific character of a person. But it can always be faked. I've seen many people fake it in order to get girls. And I've seen them breakup because they weren't acting like their feigned personality sometime after the breakup. Honestly, I can't ask those girls how couldn't they see that. But I'm sure there's a plethora of girls on Reddit who've gone through this. It's not really difficult to look through a person if we pay attention to what they're saying. But people are just attracted so much (mostly by looks or money) that they ignore those things. And eventually when the sweet mixture of chemicals that is produced in your brain starts to deplete overtime, you finally see that person's true self. Hence, your entire argument that you were attracted towards a person because of their "personality" is false. You were attracted because you wanted to be, and eventually you saw what they really were. So my question is, why not see through that first? People always say that women know everything that you do but don't react to it. It has been my experience that it is a falacy. What are your thoughts on that?