I think for 99% of journeys/users it makes perfect sense to not need a ticket office.
Most Londoners know where they want to go, how to use the Pay as you go Oyster and even top it up.
There is that 1% though that needs extra information or advice on what is the best ticket to get. I don't see a problem if the ticket office staff are re-trained or re-recruited as customer service/platform side staff and have an emphasis to help "tourists" use the ticket machines.
Ideally i'd like to see the whole pricing system reworked for a 1 journey 1 price system getting rid of the Zoning. That would surely annihilate most "what ticket do i need? queries"
I'm quite out of touch with single fair prices and been using a oyster top up since day 1 all i know is it beeps and sometimes i have to add £20 quid to it
My local tube stations at the east end of the District line have been without ticket offices, as far as i am aware, for a good few years now. The lack of Staff presence at these stations after office hours has been a bone of contention.
My grandad and father both worked for the Underground so i have a bit of a bias but as long as there are staff to assist should it be required i see no problem cutting numbers of ticket offices.
There is still merit to having them in busy locations. Banks have ATMs for 99% of transactions but there are still times, sadly, when you need to deal with a human.
AS regards contactless payments... I personalty prefer to have 2 separate cards even though it is a ball ache on buses and barriers separating the 2 physically.. Knowing i have a fall back if my oyster is empty. Stupid i know... If the new system, can itemize journies or has a separate breakdown on my statement then id be more interested.