Long distance can work if people eventually meet and spend time together. Online friendships could possibly exist without ever meeting but not romantic relationship. You need to spend time together. And you need to meet more than once. You can talk online until cows come home and be all giddy thinking you got some chemistry, but when they arrive with their suit cases, it might be entirely different story. You need more than chemistry to sustain relationships

Meeting and spending time together is paramount for relationships. But of course they can start as long distance. They just cannot stay long distance forever