One advantage that an Oyster card has over a contactless payment card is that I still feel uncomfortable getting my wallet out and finding a payment card in a crowded tube station. Even using Apple/Google Pay requires me to get my phone out and again, I'm not always comfortable doing that. I appreciate I might be a little old fashioned about this but enough friends have been robbed in London over the years to make me a little paranoid. An Oyster Card, on the other hand, has sufficiently little value to me that I'm a lot more comfortable using it.