I'm 24 currently, I probably wouldn't date someone who can't drink. Bars for me are the place I can go and officially feel adult, idk if thats how other americans feel, but thats how I feel.
In the last 2 years I've been with folks who are 20+ years older than me. It was a lot less weird than thinking about being with someone too young to go out and drink despite those people technically being closer to my age.