TfL is currently consulting on plans to axe the Day Travelcard.
The paper tickets give unlimited travel on TfL services, including bus, Tube, Tram, Docklands Light Railway, London Underground, London Overground and Elizabeth line, as well as National Rail services in London.
Under these plans, visitors to London would have to use Contactless or Oyster from when they arrive in the capital. Children would be expected to apply in advance for a Zip Card or get the Young Visitor discount set on an Oyster Card.
Speaking to residents, I hear that many elderly people who do not own Oyster or Contactless Cards will be affected, as will friends and commuters who do not live in London.
You can have your say on TfL's plans here: https://haveyoursay.tfl.gov.uk/travelcards