I’m 36 and have been with my current girlfriend for almost 5 years now - my longest relationship yet. We live together & everything else couply, just not married. I see marriage as unnecessary pressure that has a tendency to put strain on the relationship. Right now if we’re happy together we stay, if we’re not we split. Simple. Marriage complicates it.
My partner and I dated for nearly a decade before we decided to get married. It’s more important that you two are on the same page than it is for you to measure up to some arbitrary cultural norm. Even after a decade, we still laid some ground rules and made some agreements about HOW we would handle things in a worst case scenario. Prenup/postnup type stuff. People may view this as nonromantic, but I can’t think of anything less romantic than arguing about shit after the fact with someone you already broke up with.
Make sure you have your paperwork in order though. If you want your partner to be able to make decisions for you in an emergency or if you want them to inherit something if the worst happens, you should check because you likely have to explicitly set that up.