Well I know that Dropbox deactivates your account if you haven't logged in in a year, which is a shocking practice as you could lose backup data in that case. Don't store anything precious in a Dropbox account. Yes, I know, you may have a local copy, but still...
I don't know. I stopped using Dropbox when their Linux client started telling me that my filesystem was not supported anymore; they dropped support for encrypted disks and asked me to do something about it (i.e: not encrypt my disk).
I also stopped using Box because it keeps sending mfa text messages to a phone number I do not control anymore, and trying to do something about it I get asked to ask my administrator for help or to ask support. Too much hassle. I may do it.
To change the old phone number the 2FA code is sent to, I have to be logged in, and to log in, I have to have access to the old phone number.
I had also lost control over that phone number, which I've had for fifteen years, because I had to send it airtime every three months. I was abroad and I missed sending airtime by one day and it was blocked and taken from me. I asked the telco to give it back to me, they said it's impossible and it will be assigned to someone else. I asked can that someone else be "me"; they said no; it's random. I asked if I can randomly buy it back; they said no.
So, from my perspective, Box and Dropbox are as useful now as the services they set out to replace in 2007 or something.