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.

multiple clones have been available for almost 2 decades but grindr dominates so much that it's larger than all of the clones combined because of name recognition; even straight people know what grindr is and, thus, new gays will only hear of grindr unless they dig into sources that aren't mainstream (eg reddit niches and word of mouth from other gays who know about the clones).