Are they doing anything terribly anti competitive? Seems like Bumble was able to gain marketshare just fine?
I dunno that regulatory action would have any meaningful effect here. These apps come and go every few years, the users have high turnover, and there's not even an exclusive network effect like regular social media has. If you break them up into a bunch of smaller ones, they'll just re-consolidate over time.
What about a nonprofit/open-source dating app instead?
Perhaps stating some sort of concrete claim might be a start.