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.
“make up a situation that doesn’t/won’t apply to you and see if that changes your mind”
Try to see something from somebody else’s viewpoint. Basic empathy.
I’m not interested in changing your mind, OP asked for insight, this delivers it.