I think you're asking the wrong question, as there don't need to be many! You just need to ask yourself, if my files were deleted by a virus, is my backup routine sufficient to restore all my essential files?
But in general, yes it is probably true that these days, most common viruses (virii?) focus more on 'scams' like trying to get you to sign up for something (such as fake anti-virus programs). There isn't much (any?) profit in writing a malicious code that just deletes all your files - whereas writing a 'scam' virus will net cash from unsuspecting users who then sign-up to buy 'software' to 'remove' their 'infection'.
Either that, or things that try to get you to divulge bank details, or other account information and passwords. Possibly involving keyloggers, or just fake login pages.