I'm curious as to why so many people end up in the email hell, I can understand if you are a senior person at a large company or some sort of public figure/mino

I'm curious as to why so many people end up in the email hell, I can understand if you are a senior person at a large company or some sort of public figure/minor celebrity. I just run a decent spam filter and ruthlessly unsubscribe from all commercial newsletters. Things from mailing lists are auto-filtered into folders and almost everything that's left is stuff that is pertinent to projects I am involved with so it's stuff I need to read. On a busy day when I'm working on 2 or 3 projects I might get 20 emails.