In some ways, such as buying and trading stocks and ownership and such, the metaphor doesn't really hold up most of the time. The only area I could see it holding up in is by saying a person's romantic value changes over time just like a stock's monetary value does, although that's not much of a metaphor since you can just say "a person's romantic value changes over time" and you don't need to compare it to anything else, people will get it.
I think it’s kind of the opposite, using “supply and demand” or anything like that just kind of assumes that everyone is exactly the same, and nothing matters besides quantity of people. when people obviously vary a lot, and have vastly different wants in relationships. It reduces dating down to “I want a gf” instead of like, learning about people and finding someone you connect with