Does age really matter?

I’m honestly curious because something I feel like people will limit themselves or others just because of their age but should it be based on their mentality and maturity? People go through a lot of stuff at young ages and they grow up a lot faster than other but because they are still considered “a kid” people don’t take them seriously. I just want to know what some of your opinions are but please keep it respectful and especially since others might have different opinions or views.