If it's a simple solution, why hasn't someone built it?
I suspect that any such product that starts to get a significant user base is quickly overrun by people looking for cheap hookups, on the one hand, or "sugar" relationships (at best) on the other.
It's impossible to successfully steer that (to stop most of that activity). Forgo a native image service on Reddit and you get Imgur. Don't allow picture uploads on the platonic service and people will take care of the problem, they will route around it trivially. You will quickly be right back to people trying to turn it into a dating service. It's too easy to go around.
The best you can probably hope for is to swim with the current. Otherwise it will drown you. Set up a section just for dating to better contain the inevitable pressure in the system.
I suspect that any such product that starts to get a significant user base is quickly overrun by people looking for cheap hookups, on the one hand, or "sugar" relationships (at best) on the other.