Also I do most of my banking online. The only reason I have to use the bank branch is to deposit a cheque (only 1 or 2 per year so not very inconvenient) or for advice (not very useful as we have a very good financial advisor).
So for me a high street bank is no real need. But I feel for those who are in a different position.
I bank in much the same way and I believe we can deposit cheques at the Post Office although I have yet to try that route.
As our area is a retirement area lots of these people are not computer savvy and are worried about how they will manage.
How the local businesses will cope I know not, I suppose it must be possible to share a Group4 collection truck at close of business as a possible alternative to the bank.