I think the mathematics work better if they match you with "mostly compatible" people rather than "not compatible at all". Success stories are important because that's how you build recognition.
Now a days though, match group owns all dating apps so they have a monopoly in dating. Whenever a new app comes to market that's "better" (which will be, in its initial stages) they acquire. Users migrate and then they ruin. Rinse and repeat.
They recently acquired sniffies (a gay cruising app) for like 100M. Go figure.
* Recruit friends to make recommendations mimics classic searching techniques
* Can scope out a more complete bio early in the process, for both AI and Human filtering/matching
* Their long term incentives will be meet if they post cute couple pictures or generate new long term users
In theory the 'knows people you know' thing is a good vetting system for finding people to date though.
In any case, you only pay for dates you go to (unless you cancel at the last moment). Their incentive is to send you to as many dates as possible.