Retail banking, on the other hand, I totally agree with you. Basically everything that can be done in a branch can be done on your phone, faster. And the stuff that can't be done on the app can be done by calling in, which still takes a fraction of the time of going to the branch. I've personally had great experience with bank customer service, and routinely have 5 minute calls with them, whether it's to authorize a charge on my card or change my ATM limit.
Banks definitely see this change coming. It's just a question of when they draw the line between catering to the subset of their customers who prefer in-person interaction and the cost of running a branch (especially when compared to the kind of overhead that comes with running an app).
I'm more curious to see how ATM's evolve.
That said, having a bunch of physical branches provides as much an advantage as not having to buy gas when you use a horse instead of a car.
Both are relatively new entrants to the market, but their account terms/fees are so poor that I cannot imagine why anyone would bank with them. (And judging by foot traffic, nobody is) So why do these branches exist?