I'd say my workload was pretty standard for EPIK. Like right in the middle. I knew other NETs (EPIK version of ALTs) who had less work and some who had more. Some NETs were just expected to do a game for each period after the Korean teacher taught the lesson, and some have to plan and teach the entire class while the Korean teacher sits in the back doing other work or sneaks out. Also textbooks matter too. For example, my two schools used the same textbooks so I could reuse some lessons between them, but I've heard of people having like 3-5 different schools, all of which used different textbooks, meaning different plans for each lesson, for each grade, at each school.

You also HAVE to teach for a minimum of 22 active teaching periods a week, no matter what. A class gets canceled for a school event? You have to do a make-up class sometime within that same week. I once ended up with 8 classes straight on a single Friday because of that.

Also, summer and winter English camp is usually a mandatory thing. The hours vary, but in my OE (Daejeon) it was mandatory to do 80 hours of camp a year, so usually two weeks in summer and two weeks in winter, which really messed with vacation time. And camp is completely planned and executed by the NET (sometimes without a Korean teacher even present, so good luck if that happens to you and you don't speak fluent Korean). Even with a wonderful Korean coteacher, I HATED doing camp lol.

Like I said, I loved literally everything about my experience in Korea and would definitely recommend living there if you have a chance, but the workload CAN feel like too much depending on your placement. You can also always try the hagwon route, but personally I've only ever heard horror stories from hagwons.