As a gay man, I've used them a fair bit. Mostly the apps, but when I was younger I tried OK Cupid and some of the more gay oriented dating sites and while they definately have their downsides, like the catfish, the trolls, and the people who are there just to "entertain" themselves they certainly serve a purpose.
I'm quite a shy person, and once I graduated university I started to enjoy clubbing and drinking less and less. Since the vast majority of queer spaces revolve around drinking I don't think I'd have had the opportunity to meet the partners I've had, including my current partner of 6+ years, if it weren't for dating apps.