Why don’t many people in the world stay as a bachelor and a bachelorette and instead, have a partner and then get married? Why do many people end up with a partner and then get married? Is it not socially acceptable to be single forever?

It is more “socially acceptable” to get married, have kids, have the long-term career, etc. And to settle down and get married is one of the main pillars.

I think if we just trust our guts and not rush into things, we can be happy in a relationship that is long-term and has the same commitment as marriage but without the piece of paper. A lot of divorces could have been prevented if they went against social convention and waited to get married, or not got married at all.

Reference: https://www.quora.com/Why-don-t-many-people-in-the-world-stay-as-a-bachelor-and-a-bachelorette-and-instead-have-a-partner-and-then-get-married-Why-do-many-people-end-up-with-a-partner-and-then-get-married-Is-it-not-socially-acceptable-to