Wigs actually improve the appearance of most women. If the whole society took on the custom that married women wear wigs (like 18th century French aristocrats) they would appear more elegant. But that, of course, is very different from the argument about religious modesty.
Also, as she notes in this article, wigs are very hot in summer. They must be very unsuitable for life in Israel.
I puzzled as to the benefit of an extremely expensive and sometimes uncomfortable wig, as opposed to a scarf. Every other head-covering group I can think of wears some kind of non-hair (as it were) covering.
Is there something in Jewish history or theology - as opposed to Christian, Moslem, or none-of-the-above - that makes wigs the thing?