Bandcamp has always felt like it should be someone's lifestyle business, like gumroad, and never seemed like it was trying to be a "business" that needed to add features or obsess over hyper hocky stick growth. If it tanks it's because it should have stayed as a weekend side project lifestyle business and never been bought by someone that wanted to convert it into a money printing machine because it never can be that type of business.
With that said, if they do tank, it can seriously be replaced by someone in a weekend, maybe 2 :)