How do you stay productive in cafes? Does it really work?

J.K Rowling said in an interview, that she would sit in cafes for hours to write her book. So, I tried this with multiple cafes as well, but it wasn't a great experience. The cafe got crowded during twilight and I couldn't focus on my work. I came back home without completing a single task, wondering if there was a problem with me. I'm curious to know, does this happen with you too, and how do you manage to stay productive in cafes?