The ability to configure enabled state of a button based on an expression has been a seismic improvement for architecting app logic. It makes error handling so much easier and at times even has prevented me from adding steps.
This same pattern could be applied to inputs for similar benefits. Preventing users from accessing input fields could be done in an extremely similar way-- I believe just setting the html element to a status of disabled.
For a simple example, this would allow for Add Record and Edit Record pages to be very easily consolidated into one step, where certain fields are usable if the record is null, and certain fields are disabled when you are editing. This way certain fields could be locked from editing.
There are probably many other examples. This would also have the benefit of ignoring the disabled input field while tabbing through an application.