What I like about email is that it's one of the last bastions that are still under your control and work for you, not against you. It's not siloed in some "app" who wants to "engage" you, it lets you set up rules even against other companies' will (I'm sure no company out there wants me to be able to automatically filter out their marketing spam - or worse, redirect it back to some high-level employee and waste their time) and all your data is still within your control and you can build custom software to deal with it if needed.

I pretty much always opt for email notifications as opposed to some proprietary system - this allows me to decide what to do with them (including turning them back into a push notification by using something like Pushover, while the official app's push is disabled because they mix in marketing spam with useful notifications) even when the sender would rather not have me do that.