The software isn't the complicated part of dating apps; it's getting a user base that takes a lot of work/investment. And then finding a way to monetise that user base. Which often involves actively trying to stop them finding partners and leaving the app while pretending they're trying to find people their perfect match - although Grindr is more of a hookup app so they don't have to worry about that so much.
Match Group has a monopoly on most dating apps/sites (not Grindr, though) and it's incredible how much worse most of them have become since being bought out - all in the name of monetisation.