Those sites do help some people.
The stigma against the Internet is irrational. It’s kinda like saying phone is good but mail is bad or the other way round. Internet is just a medium and no, it doesn’t mean you don’t have a life.
Profiles on dating websites do some of the job parents, friends and others did when introducing people to each other in the past. Or the footwork which we all do in all our relationships anyway: basically finding out about the qualities of the person we’re about to get involved with. Or simply finding the potential people.
It can actually be superior to meeting people out in the street or when going about your business out in the world, because you get some data and some answers spelt out for you, e.g. attitude on certain aspects of the faith, including invalidating stuff. It can be superior to penpalship because you get a photo.
Sure, people can lie. They can and do in “real life” too. (It’s easier to lie online or to keep track (due to having logs and/or keeping sent messages) but real life conversations make it easier to get away with inconsistencies than something you can read again after some time and compare.)