It only goes up in certain countries. I live in France and it is increased every spring.b When I move to Thailand I will lose the increase as things stand.
My wife was accepted but she had a house in her name. I submitted her deeds. Also she had children / grand children so I put that in the application. As people have said it is the strength of your argument that she is not going to overstay that is critical. She had no money in her account and I was her sponsor.
Just a caution... when I last checked, money in a wise account is not protected as a UK bank would be so I haven't left large amounts in although the interest was tempting
You will need verification of identity before you can open an account but it doesn't take that long.
I've had an account for a while and my pension is paid into my UK account. I live between France and Thailand and change money when the rates are good. It's much cheaper than using bank transfers