Marriage doesn't help! "Partnership" is recognised by immigration, and that requires living together, sharing the same address and bank account for a year.
This is because of a cultural shift in the meaning of marriage. It used to be one man and one woman, for life. Divorce, polygamy, homosexuality, and marriages of convenience changed that definition. I'm not trying to get distracted about whether those groups of people should be allowed to marry - that's a different political debate. The outcome is that marriage doesn't matter for immigration any more.
As soon as I get married, I'm going to have sex! But that might bring babies. If those kids can't have nationality, or risk their parents being separated by visa issues, I want to delay having those kids. So I want to get PR before getting married.
I’m not sure why you threw in a dig at homosexuals in your little immigration rant. That’s probably why you’re getting downvotes here. Plus it erases a lot of goodwill you might be building up.
Also btw, there is no modern state that recognizes polygamy, especially for immigration purposes!
Ps: marriages of convenience are ... classic marriages. That is what marriage used to be. A business or political arrangement. For convenience.
> For her to move to the UK requires her to meet income requirements of £18,600 per year
What about if you got married?