I don't think that everybody hates mail, I don't have majority of problems that were outlined in the (now deleted) 25 problems with mail that was pushed forward

I don't think that everybody hates mail, I don't have majority of problems that were outlined in the (now deleted) 25 problems with mail that was pushed forward by Hey. But I think that there is a growing set of people that have very particular problem with mail. People that are somewhat public figures, such as podcasters, journalists, YouTubers, app makers and what have you are quite regularly complaining about email. I think this is because they need to keep a public address open towards real people and there is a large power bias. A hundred people can send you a message with a bug report or a correction about stuff you made, it takes them 10 seconds each. But for you to read and answer individually it would take you hours. I suppose that Hey and other solutions with all the triage and snoozing is for them. Systems like Slack are kind of orthogonal to this.