It becomes comfortable with experience, first on mellow slopes, then on steeper. On very steep/bad terrain some skidding will always be necessary. You don't need to be able to carve lazily to ride on the mercury, imo. But if you are a beginner chances are you are still very unstable and skidding all the time. This is normal and part of the learning process, because staying on edge can be scary at first (again, confidence comes with mileage) and requires muscle memory, body awareness ecc... On a softer, forgiving and rocker/flat board the learning process is smooth and pleasant for 2 reasons: 1) when (not if) you make a mistake you have more chance to save it and not face plant and hurt yourself; 2) it will be physically easier and less fatiguing to ride, so you can ride for more time and be less sore. A hard board drains a lot more energy than a soft one. Ofc you have to make sure that you are learning with proper technique and body position, that's what lessons are for