Why would this guy I have a crush on match with me on a dating website but then never message or reply?

You know how attraction works, don't you? We are born with a subconscious that records every second of every day of our lives. So if someone isn't attracted to you, it could be because you have a nose like his third grade teacher who was mean to him. If they are attracted to you it could be because you have a trait in common with his grandmother, whom he adored.

Starting new relationships is stressful because there is almost always that period of time when we simply don't have the data to know if that other person is attracted to us or not. We have to be patient because time will tell. In a case like you describe it could be because he doesn't want to date someone he knows, because he's not attracted to you, or because something big just came up in his life and he'll get back with you later. Time will tell and my advice is to wait and do nothing about him. Most people don't like to feel like they're being chased. Most people will fall harder for someone who acts and thinks like a winner.

Meanwhile, keep your eyes and your options open. There are, after all, over seven billion people on the planet so the numbers are on your side.

maybe he thinks you're a psycho.