It's a bad market to take on because the competition is 'commodification by Google/Apple/Microsoft'. If you do a great job you compete with Dropbox on price and quality, and if you do anything short of that you compete with the office suite versions of the same product, which are effectively free to their subscribers (because file sync is packaged with other services that they're buying anyway) so getting people to give you money is very hard. Dropbox itself is perpetually at risk of being commodified out of existence; their constant battle is finding ways to make sure their customers can still justify paying for them as a separate service.

(at least this was the ambient understanding internally when I worked there a few years ago)