Okay I agree with the general gist of your message but the facts are wrong

. 50% of marriages in the U.S. end in divorce, not 99%, lol. Also I didn't mean marriage was hard because of the personal factors although that definitely does come into play.
It's hard mainly because it takes years to prove the marriage is legit and even then it's very costly and a long process because you have to prove you came in legally, which if you haven't then in that case you'd have to apply for a waiver, and even that is hard to get verified.
I only know this because my professor married an undocumented and I took a course with them on illegal immigration.