IMO Apple is long overdue admitting that putting navigation buttons on the top bar was a mistake. Fine in the era of the original iPhone, but as phones get progressively bigger and taller, less so. The swipe back gesture works in most situations, but I was a fan of Allen Pike's mockup of bottom navigation on the iPhone X (or, "Pro", at the time):
https://www.allenpike.com/2017/developing-for-iphone-pro/
Having navigation at the bottom is one of the few things Android got absolutely right at launch when compared to Apple. But back to notifications, Android isn't great either: if a new notification arrives while I'm swiping old ones away there's no consideration that I might not want to swipe away something I haven't even read yet, so it disappears immediately and with no way to get it back. Frustrating.