I know many adults who believe that splitting bills is a normal and reasonable thing to do.
I know many adults who believe that splitting bills is a normal and reasonable thing to do.
These are etiquette rules, which have their benefits. Since nobody is forced to follow etiquette, they help you to learn things about people.
Generosity is one of the easiest life hacks to find out who is friendly towards you and who is not. If you buy them a drink and they won't buy you a drink back, that's a tiny cost for you to know what kind of fellow you're dealing with. If they buy you a drink and then asks you to transfer money to them, you also learn something about them. If people splitting bills want to sit and count to make sure that everybody pays exactly for what they had, then you learn something. And so on.
If you invite people for dinner a few times, you will learn something about that person whether you wanted to or not.