I know people who hate black shoes. Nevertheless, most of them own at least one pair of black shoes, simply because sometimes black really is a good choice, and it's only one pair. Depending on your level of distaste for dark brown shoes, perhaps you could adopt a similar approach to the matter.
However, there is nothing inherently wrong with suede shoes in dark brown. If you like the shoes, and think you'll have occasion to wear them, feel free to buy them. (Nor is there anything inherently wrong with a tan suit, if you like the suit and think you'll have occasion to wear it.)
But that having been said, when it comes to shoes, it's often sensible to spend a little more money to get excellent quality. Then properly maintain and care for the shoes. Doing so can result in many years of excellent service from them. (To further complicate matters, even with proper care and good quality shoes to begin with, it's likely fair to suggest that leather shoes will tend to outlast suede shoes.)