It's more nuanced than that. I have to use Oyster over contactless because it's the only way to get the 1/3rd discount when you have a 16-25 or 26-30 railcard. They can't currently be connected to a contactless card.
Re:Field notes: London, England (2018)
by chrisseaton on Tuesday January 15, 2019 @06:24AM
(#18910368)
I thought they also grouped into a week ticket?
TFL gather together all journeys made per day, so no matter how many journeys are made with the same contactless card there will be one charge made. However, an awful foreign bank might charge $2 per transaction, which could be more than the refundable deposit on an Oyster card.