Okcupid still exists and operate in this manner. So do other platforms. The reason why it does not proliferate like it used to has to do with the short attention span of the population, and in general, the attention economy. You can’t have people answer 1100 questions anymore.
You can, however, put pretty people on the app for them to swipe left or right, and that drives people way more than Doing work to get a match. Unfortunate but true. So the people who opt in to this difficult end are not enough to drive the platform anyways. At least, it could never be anything like when You and I used it ages ago, when everyone was down for the cause (and had the attention span for it too)