Because it would be more comfortable for her as well ! I wouldn't mind trading being the respected mayor of a small town living in a mansion (with all the modern technologies etc that everyone else developed a taste for as well) over being an Evil Queen leading peasants who hated me either haha. Also I think people truly underestimate how badly the people of Storybooke felt under the curse, it was much deeper than just Regina messing with them in superficial ways. It was like a deep, constant feeling that something is wrong with you but you don't why and no matter what you do you can't fix it and every decision you make is wrong because you don't know who you are.