There are pros and cons for either demographic: whilst being older may be ideal since not only you bypass age restrictions, you also have the capability on purchasing it with your own money without having to ask parents for that given that you have employment and recurring income. Gaming as a kid gives more time without having to dwell much on responsibilities that adults have to worry about but at the same time are held by school.
I think gaming as an adult is better honestly. But that’s thanks to all the experience and understanding built up from gaming as a kid. I would not have had the patience or understanding to play and complete some games as a kid that I was able to do now.