All of my personal notes, and work notes, are stored in Evernote. My cell phone, a galaxy note 4, synchronizes all of its notes to Evernote as well. So even if I lose my phone, all of my personal notes are safe. Maybe not so much from prying eyes, but I haven't lost the information. And since it's not of a private nature, that is no big deal.
Anything that is personal, is in an encrypted volume, or in the event of passwords it is in an encrypted database, even in the cloud.
My personal preference, is Dropbox. However I get more free storage from one drive, so that is where I put my big stuff. My wife does not share the one drive stuff, only the stuff in Dropbox.
So for me I cannot tell an individual to simply avoid it. I have to tell that individual to evaluate your needs, and see if the technology is appropriate.