Out of interest, why do you choose not to use online banking? A lot of the mundane stuff is just so easy, paying bills, transferring money to family etc etc.
They're hardly complicated, just delete all the apps they're never going to use.
As for a bank, if they find a smart phone intimidating surely you're not going to let them go to a bank to discuss their finances on their own? (apologies if that sounds condescending, it's not meant to be)...