I actually don’t mind having all emails coming into the same inbox, but would beed to know/see where they are coming from easily as the email they arrived to can make a big difference.
Like for the calendar have a colour code for inboxes which shows, as a label, dot or smtg similar (not the full line or it would become unreadable to the eye).

Bonus: keep the colour coding as default for calendar events.
I am mac and iphone, but seems to not be a feature at all.