There is also the question of how long emails and other transmissions over Yahoo or similar services is retained. I actually stuck with Yahoo rather than considering gmail because I read a couple of years back that Yahoo purges old communications after a few years, but Google retains it indefinitely, including search history.
Don’t know if that is still correct.
scroogle scraper protects you from google.
There is an organization that uses grant funds to catalog every website page, every day. Many of the links stay live too. For example, you can go and look at the Apple website from this date twelve years ago and see exactly what it looked like. Every shred of info on every page is being cataloged and saved.