If you did better with your warlock main warlock but none of the classes are easy mode, honestly I picked warlock because I knew that that's what I would like and I learned it in and out had a few rough times and even more good times in the crucible because I play best with warlock, every class has something the other classes don't and if you learn the class well enough you won't have to try as hard with a certain class over another. Just saying you probably did better on your warlock either out of lucky games and skill or your play style just matched up with a warlock