Not everything needs to be “fixed”. While Mai being insensate is a bit disadvantageous for her and may be aggravating to some people, she deals with it just fine and is able to self-medicate to an extent with winterstem. Most importantly, she’s perfectly fine with things as they are as far as we can tell because she can manage and her health (both physical and mental) isn’t suffering. And as Observer pointed out, it’s a side effect of her gift. There are always tradeoffs to having any sort of advantage/disadvantage and for Mai and Miko, it’s being hyperaware of everything as a result of being able to directly see auras and spirits. Their respective neuroses simply comes with the territory and is firmly intertwined. There’s no cure for that; they can only cope with it their own ways and frankly they’re managing just fine.
I personally see their condition as similar to neurodivergence IRL. The cons exist and people tend to be concerned about them (to put it mildly), but we just learn to cope with and manage them, while making the most of the pros we have. Whatever the cause of these conditions, they are simply natural variations in the population with different sets of adaptations.
And frankly, why would you force everyone to be the same? Even neurotypicals have their variations and have differing personalities. Not everyone has to be a bubbly social butterfly regardless of any medical/spiritual condition.