Hi Rabbi, I’ve alway been interested on how sheitles are allowed. It makes sense to me that women should cover their hair but isn’t wearing a sheitel a bit of a loophole - if one can’t show their hair how is wearing a different sometimes much nicer hair really fulfilling the mitzvah of covering one’s hair and how is this such an accepted thing in nearly all communities. I’m grateful we can do it but it’s never made sense to me. Thank you

You are correct, and in fact there are three approaches to the issue. Rav Ovadia Yosef does not allow married women to wear wigs (and so is the practice of many sefaradim and many women in general in Israel). The second and more predominant approach outside of Israel is that wigs are allowed but they must be modest and not alluring. The third approach is that today it's so difficult to get married women, especially ba'alei teshuva, to cover their hair, so at least they should wear a wig which serves the letter of the law, if not so much the spirit of the law. There's no doubt that to be intellectually honest, the first approach is the best, but it's also obviously better to wear a wig which covers your hair properly (leaving out just that permitted 1 tefach= 2 cm. across the width of one's face) rather than to wear a minimal "symbolic" or partial hair covering.