>>27739862May's designed to look like a teenage girl. And back when Hoenn was airing we were all a lot closer in age to her than we are now. Just because she didn't age and we did over the last decade makes no difference.
It honestly felt like May was purposely designed this way because GameFreak and the anime writers knew the original kid fanbase were becoming teenagers in Gen III, so they needed a teenage looking girl to keep their interest. It worked for me.
The moment AG1 aired I never looked back.