Everyone I know recommends trying them but I have yet to meet or know someone who has had a long-term successful relationship come from a dating app. It just seems like most people use them these days as a way to hook up or beg for money.
I would say no. From my own personal experience, I have only had a few matches where I was interested back and of those few, half were just women (or men posing as women) looking to get money just as you mentioned.
They can be for the right person/right people. I have a friend who met his fiance on a dating app. They are getting married in December. They had been together for almost 3 years now.
Maybe, maybe not. It depends on which one you are using and what you are using it for. You have to figure you will run into people who are only looking for hook-ups and hand-outs these days which is unfortunate. You are probably better off meeting someone on a social platform vs a social dating app or site.