i recently discussed the development of a new application for a customer. one of the important aspects was that the app would handle data that would have to stay local. despite that my thinking went like this:

if i develop it as a webapplication, then i can do all the work on my computer, test with various browsers and deliver a working result. if the customer has issues, i can likely reproduce them on my machine.

but if it was a desktop application, my feeling was that testing would be a nightmare. i would have to set up a machine like my client, or worse visit the client and work with them directly, because my own machine is just to different from what the client uses. also not to forget distribution and updates

in short: web -> easy. desktop -> difficult.