Going from one job using a "startup-y" Gmail company account to another job using a "corporate-y" Outlook solution was a tough transition. Outlook has loads of features, but the UI simplicity (relatively speaking) of Gmail makes most of them unnecessary in the first place, plus it was a little less frustrating to use. Meanwhile, Gmail still had calendar events, reminders, google drive integration, etc. in ways that seem on-par with features in Outlook.

Disclaimer: I'm not a PM/executive who has to juggle meetings and communication all day, so maybe I just ask less of email.

Edit: clarity