Down payments and savings don't prove commitment. The point of signalling is to prove things.
https://en.wikipedia.org/wiki/Signalling_theory
If you change your spouse, your savings account remains the same. The ring you paid for is gone.
https://en.wikipedia.org/wiki/Signalling_theory
If you change your spouse, your savings account remains the same. The ring you paid for is gone.
I like to think humans are pretty good at developing alternative strategies.
Besides, if you get divorced, you don't get your down payment back anyway.
Or maybe if you can find a way to mimic the effect, but make it useful, you have your hands on a very valuable startup idea.
I guess it would be something like helping friends move, which is considered a good signal for true friendship. I don't know (not an expert on this), maybe if you find a way to "help your spouse move" for the equivalent worth of 3 months of your salary, you are good.
Why don't you get your down payment back if you get divorced?
The whole marriage thing is also extremely expensive. I suspect for similar reasons - so that people think twice before throwing it away. In that case they also have angry friends and relatives who invested into expensive travel and presents and probably wouldn't be too happy if it was all for nothing.
But then I've also been with the same person for 19 years who also things the ring this is a scam.