For background, I'm married to my dual, and our marriage has been really good and easy and has had longevity.
But I know lots of people in non-dual marriages who also seem very happy and whose marriages have longevity.
I feel like duality makes my marriage easier, but on the other hand there are things unrelated to scoinics involved that make my marriage easy too - similar views on politics, religion, how to raise children, etc.
My friends who are in happy non-dual marriages talk about how they "work on" their marriages, by doing things like having regular date nights, spending certain amount of time each night talking about something other than their children, etc. My husband and I don't have to do anything like that or worry about it, but maybe their work is beneficial enough to make it even better than my easy dual marriage? I've only been in one marriage so I can't compare.
The one thing I do feel confident about is that duality is not the end-all-be-all in relationships. I feel like people should, when they're young and of dating age like so many people here are, go out into the world and just date and enjoy themselves, without so much focus on type. What if there is a wonderful relationship with a non-dual available that you miss? What if you end up with a dual with whom you have such different views on religion or politics that you just sit and argue all the time, albeit argue very well and effectively due to compatible communication styles? And what if you've mistyped yourself, or the other person you're dating or not dating based on Socionics? It all seems very risky to me.
(This is not based on any specific person. It's just a thought I had.)