I used Superhuman for years. I switched to Shortwave about six months ago. Superhuman has bells and whistles. Shortwave organizes emails in a way that allows me to process them quickly and intelligently in a way I never could before.
Once I got my bundles dialed in. I can open Shortwave and, at a glance, see the entire big picture of what's come in and instantly know where to put my attention next.
I also have whole categories of emails that Shortwave knows not to even both showing me until, say, Tuesday at 1pm.
Their AI alone has saved me lots of time. I'm not one to have an AI compose anything for me, but having it summarize long incoming emails is a godsend.
I HIGHLY recommend this app.