Drinking age in America. Ridiculous?

I'm a flight attendant, and recently went to San Diego, I got turned away from so many bars for being under 21 when I just wanted to go in and eat. I just think it's really silly to have such a high drinking age! Learn to drink younger then you're less likely to fuck up when you're an adult. I can evacuate a Jumbo Jet, deliver a baby and use a defibrillator, yet I can't have a cocktail 😂😂