Married at 23 (wife just turned 21) straight out of college. We were both very immature
Also totally anecdotal: Exactly the same for us, up to this point. Now I’m looking at 36 on the horizon this year, and she 34, and we’re still both quite happily married.
My only point being: it just depends on the people. It works for some, and for others it doesn’t. I wish I could tell a person which kind they’d be, but I can’t.
I will absolutely say, however, it’s gonna hurt a whole hell of a lot less to simply wait a bit longer and be sure of what you want, and that you’re both in agreement on the major things. It doesn’t mean you have to wait in order for the relationship to succeed, but it sure would improve the likelihood that it will.