Even with this, there were many surprised people. I'm still amazed at all of the people that can ignore everything and just open their IDE and code (and maybe never see teams or email)
Add in the various spam (be it attacks or just random vendors trying to sell something).
At some point, people start to zone out and barely skim, if that, most of their work emails. Same with work chats, which are also more prone to people sharing random memes or photos from their picnic last week or their latest lego set.
My #1 method of keeping my inbox clean, is unsubscribing from newsletters.
I also set up a rule to auto-delete phishing test emails based on their headers, which annoyed the security team.