It feels like a common trope among businesses of a certain size, when someone asks "Why does nobody read the emails?" without looking at the inbox from an engineer's perspective.

My job is not to read emails. I don't open a Gmail window with 200 unread CC'd responses and think that it's my duty to untangle that. I work on what I'm paid to do and wait until I'm told otherwise by my manager. The reason every single email client doesn't default to reply-all is because engineers are conspiring together underground to stop the unjust suffering and PIPs caused by missing the needle in the email haystack. Company-wide emails are the single point-of-failure that necessitate alternative communication platforms like Slack.