My experience has been different.
I’ve been involved in a few legal matters over the years where email discovery has been done.
Going back and re-reading emails you sent years ago is a pretty enlightening experience.
What I have found is if you have the right intentions and act reasonably and responsibly, old emails often show that to everyone and can be valuable.
Being able to go back over old emails is also a great way to jog a foggy memory.
So while I understand the challenges with having a lot of written and discoverable emails “on file”, I would argue they they often can be quite valuable.