Dating apps can be where people go shopping, but it can also just be a way to filter for people you wouldn't ordinarily encounter doing the things you do day to day. In that respect, they're great.
An additional anecdote though as an in-between of both of ours: my mother in the UK met a man from Canada in a chatroom over twenty years ago, divorced my father, and they're still married. Not to say that it has always been smooth sailing at times for them (he's got paranoid schizophrenia, she's physically disabled now), but they're happy, so meeting people via software evidently does work for some people.
I mean, look at us, we don't know each other, but we're having a conversation, so if that idea is extrapolated to a dating app, sure, I can buy into the idea that they can be effective for some people.