I was just pondering this today, in terms of how much data and objects I create in a Google or Microsoft account, for example, and then they create a burden of cost and maintenance for me down the road. Especially deleting old emails and photos. That's arduous and sometimes poignant as I flush away my personal life story.
Cloud services make difficult and sometimes even byzantine processes for deleting stuff, and it's often impossible to operate en masse in order to clean up swaths of stuff quickly and efficiently. It's in their interest to retain everything at all costs, because more used storage can mean more profits. Cloud services also profit from unused storage, because if they're charging $20/year to 100,000 users who use 2% of their storage space, ka-ching!
It irks me to this day that standard or even advanced filesystems don't include "expiration dates" or "purge dates" on file objects. Wouldn't it be logical, if an organization has a "data-rentention policy" that mandates destruction after X date, that the filesystem simply purges it automatically? Why does this always get delegated to handmade userland cron jobs? Moreover, to my knowledge, nobody is really interested in devising a way to comb through backup media in order to [selectively] destroy data that shouldn't exist anymore. Not even the read-write media!
Google is now auto-deleting stuff like OTP SMS messages. I'd love it if auto-delete could be configurable account-wide, for more than just our web histories and Maps Timeline and stuff. Unfortunately, to "delete" cloud data means it still exists on backups anyway. But without deleting data in your cloud account, it becomes a juicier hacker target as it ages and accumulates personal stuff that shouldn't fall into the wrong hands. Likewise for any business, it behooves them to delete and destroy data that shouldn't be stolen. At least move it offline so that only physical access can restore it?
I will say that modern encryption techniques can make it easy to "destroy" data, simply by destroying the encryption keys. You can quickly render entire SSDs unreadable in the firmware itself with such a command. Bonus: sometimes it's even done on purpose!
But even deleting data presents a maintenance cost. So if 90% of an org's data is indeed crap, then 90% or more of your processing resources are going to be wasted on sifting through it at some later date. Imagine when your file formats and storage devices are obsolete, and some grunt needs to retrieve some record that's 30 years old, and 90% of your data was always crap. That grunt is hopefully paid by the hour. We really had this happen at a few of my jobs, where we had old reel-to-reel backup tapes and it was difficult enough to load the data into a modern SunOS machine.
https://m.xkcd.com/1683/