The unforeseen cost, of course, is that those extra features hurt usability.
But we know all this. There is plenty of literature on the subject, and good usability is table stakes for a modern product. If your product isn’t usable, your business is in a dangerous position. Maybe you can get by in the short term by boasting your killer feature set; but the fact is that if people can’t figure out how to use your bells and whistles, you’re going to feel it on your bottom line sooner or later.