Conversions are always attractive in real estate because they are nearly always luxury. When I was active in that business, the main problem my bosses had Was rezoning. If they got over that hurdle, they always made a killing.

Even before my time, conversions were enormously profitable. In NYC, long ago, converting warehouses and factory spaces to luxury lofts was enormous business. I don't think people should dismiss the amount of money to be made on conversions. The main drawback is that the areas the conversions are in become even less affordable. Which may be more than offset by affordability increases elsewhere in the city.