It's often just guys trying to be nice in the human "puzzle" of courtship. We are animals, and we have evolutionary roots. Look at how much of the animal kingdom practice mating rituals of trying to seduce/impress/wooo. Of course, it's a completely individual decision, and something for you and your date to ultimately handle.
However, some of the modern responses and "hot takes" on something like this will have your eyes roll out the back of your head. If someone offers to treat you every now and then it's not sexism to accept or some slight on your femininity/masculinity. Reciprocation is often expected too, and that's not sexism. It's real life and what humans do, what comes around often goes around in happy relationships. Making your partner smile/laugh/feel happy is a pleasurable thing. Money isn't always the answer for a balanced relationship, but sometimes it is used to elicit a favourable response (we all like presents/being treated/shiny things). Sure, if someone is neurotic enough to have everything always split equal to the last penny, that might be a bit mental to live with, but you do you and ultimately it's between you and a potential partner to see if you're compatible.
Alternatively, if someone never pays for anything it can seem a bit mean, but again, it's up to you to navigate that relationship with your other half. Personally, I find splitting bills a bit "cold". Someone outright paying for one turn, another the next, seems a bit more fluid/natural to me. Ultimately I would just find myself wanting to pay for most bills anyway, but it's just a kindness thing with my personality. Definitely, on a first date, I'm going to attempt to take lead and offer to pay.