The problem comes when you buy a modern digital camera.. my Canon DSLR is configured to write both raw- and jpeg pictures to the card. That's about 26-27MB of storage for every picture. Take a few videos (it's actually a great video camera) and it's good to have a pocket full of large SDXC cards. Dump them to the PC, it runs full quickly. Buy external harddisks, store in triplicate, and soon you're buying 3-4TB disks as candy. When my mobile phone carrier force-"upgraded" my contract to a much more expensive one they told me "it's great, you get 5GB storage in the cloud included, you can store all of your photos there!". Yeah, right..
But for the period 1989-2000, or maybe up to 2003, the total of my compressed email was around 10MB. And I had a lot of it - I got hundreds a week. A 3-week holiday could leave me with a backlock of thousands. But all this email was just text, and people didn't quote insanely (Lotus Notes, with their non-threaded email program, and the extensive corporate use, has a lot to answer for. It trained a whole industry to a habit of letting every email contain every previous email in the conversation, quoted in full).
These days I seem to need 10GB instead of 10MB to hold my emails for a similar period. Or maybe 15GB. Even with deleting as much as possible. And I can't delete it all. I still need to search for stuff that is ten years or more back. Just recently somebody asked if I could remember some technical issues from 2004.. and I could, because I had enough details in my emails from then.