Many years ago™ OkCupid actually had a good system, before it revamped itself and got bought by Match (Tinder).
In the old version of the website, you could answer any amount of questions from a huge catalogue of sometimes very obscure and specific questions and look for people who had very similar (or very different) answers overall. You could chat freely with everyone and had the option to look just for (platonic) friends.
I had incredibly interesting discussions with people who were at the opposite spectrum of my answers. And I made a few acquaintances and two amazing friends who still are my friends today, one is even my roommate for 8 years now! I also found a group of white hackers and Linux enthusiasts for real life meetings and we still hang out occasionally.
Two other friends of mine looked for and found romantic partners there and they are both happily married to the partners they found via OkCupid back then.
It went all down the gutter when people used the "platonic friends" option to get into your pants.
And when OkCupid tried to make more cash by pushing into the sex/romance market more and copying dating apps.
I don't think something like this would work anymore. Dating apps and the weird culture and thinking about a "sexual market" seem to have broken humans or something. This asinine idea is just another symptom.