You won't build technical or design expertise, but I can see it being something that's easy enough to do as a side gig or as an experiment to see what it's like to publish a game on Steam or wherever. You can use that to decide if you want to invest more effort into it, while also making a bit of money. Low risk, low difficulty, low reward; perfect for learning.
To be honest, "erotic city builder" is such a novel concept that now I want someone to tackle it.
Unless you're doing a very unusual city builder I guess.