I like form submissions too, but it's not for everywhere. For example, file uploads using multipart form submissions is a poor user experience - you cannot put

I like form submissions too, but it's not for everywhere. For example, file uploads using multipart form submissions is a poor user experience - you cannot put in a percentage-complete bar anywhere because there is no way to determine how much data was transmitted. When a file upload is taking 5m, the user is liable to think that the upload failed, and then retry, or give up. Very poor UX. Other than that one exception, I cannot really think of any other place in which form submissions are the inferior choice.