It’s really common for people to accidentally click a button twice. Yeah that’s what denouncing is for.

My favorite example of doing it wrong is a log in form: if the login button is clicked twice, the server would reject the login because the first click has already used up the one-time token so the user gets an error page.

But I think the biggest problem is that people either apply denouncing to all buttons in a UI (like turning it on within the framework they are using) or apply denouncing to nothing. So there really isn’t a culture for carefully considering which situations warrant which.