I don't agree.
If USCGA is your dream, you don't lose anything from reapplying until you no longer can. That doesn't mean "do nothing." If you aren't accepted the first time, assume a year of doing nothing won't help (not to mention, if you did get in, the classroom work would be challenging for someone who has taken time off).
I had a number of classmates in their 20s. They got the name "grandpa" because they seemed old at the time (now they seem young).
You'll want to remember that the other officers are OCS grads, direct commission officers, some that make LT from CWO or, I think, CPO (to a limited extent).
OCS isn't a guarantee.
So, if USCGA is your dream, and you don't get in on your first try, keep applying while you move forward with other plans, and hope it happens.