Whoever makes more money should pay more.
I paid more in my first two relationships (my idea). Unfortunately, it led to them both also 'borrowing' money from me that they still owe me 20 and 17 years later respectively, but what can you do.
The third serious partner made more and subsequently paid more (his idea) but he was contradictorily an abusive arsehole about it too.
The next one made a lot more but insisted on 50-50 after the first few dates, but was also very happy to come to mine for dinner and eat steak and fresh fish (while he lived at home, gave his mummy 'keep', and the most I ever ate there was a prawn salad one day) and pretended to agree to pay towards my shopping bill the next time I was going to cook for both of us (but never did).
Now I'm happily married and my husband, who makes significantly more than I do, pays for everything (which, given that I'm now a SAHM and a housewife, only making 'parental leave' money here, is fair enough).