OW Training routines?

Hi everyone- I’m still pretty new to the forum and had a question specifically for someone new to open water swimming. Over the past few summers I’ve swam a lot of .5 to 1.0 mile open water pond swims. My main problem is breaking out of my routine and going longer distance like the 5k to 10k races. I’ve been reading how some people train by jumping in and just doing non stop distance. It kind of appealed to me as I was reading about a swimmer who does a 1 mile pool swim (no breaks) 3 times a week. Right now I’m sort of used to training on a pyramid 100,200,300, 400,500. However I’ve been thinking possibly the non stop mile swims may be better from the endurance standpoint? Thanks again everyone. Let me know if your looking for a training partner in Massachusetts!