It’s possible that dating apps face adverse selection. Basically, a new app starts up, and hopeless romantics looking for real love begin flocking to it. But so do sleazy types who lie on their dating profiles. Over time, the earnest daters go on a bunch of bad dates, encountering people who have no interest in real relationships or whose profiles are completely misleading.
Like lemons driving good cars out of the used-car market, maybe sleazeballs push great catches out of dating apps and ultimately ruin the quality of the whole app experience. So people go to a new app with the hopes of finding something better, and the cycle starts again.