Wife and I have been with Kasikorn for 20 years. We have both individual and joint accounts. Individual accounts have both on-line and on-app banking - both Thai and English language options. The joint accounts, for whatever stupidity, are not accessible except at the ATM or the bank - it is what it is.
That said, both the on-line banking and the app are very good, as is the service generally; provided you understand everything is on paper, often in duplicate, with much serving little purpose beyond job creation.