Why do ferns grow in humid shady places?

One of the reasons for growing in wet areas is that many ferns can survive in the shade, and many wet areas are in the shade. Ferns are by and large experts at surviving in more marginal environments where they thrive. However, there is a large group of ferns that actually prefer rather dry areas. Notably, many of them are apogams, which means that new ferns can grow without cross fertilization, which is an advantage due to the lack of available water.