Very little.

The overwhelming majority of businesses won't switch their booking system unless they have a truly compelling reason. A large proportion of small businesses still use pen-and-paper to manage their bookings and have no intention of changing.

There is still a non-trivial market for dot-matrix printers and NCR paper. Many national retail chains use terminal emulators for their Point of Sale systems. For perfectly understandable reasons, businesses tend to be very conservative about their technology choices. Their current solution might not be perfect, but they know that it works, for a value of "works" that is compatible with their business remaining profitable. They know from experience that new technologies are often more trouble than they're worth.