Why can't I update a row with a Form?

I'd like to allow users to update information in a row via a Form. I like the user interface of the Forms and would prefer to keep users away from the spreadsheet. I know about locking information in the spreadsheet and that is not what I want to do. Our spreadsheet has a large number of columns and I want the user experience to be kept simple. Especially when information is updated from a mobile device in the field. We have a unique job number for each row and I would like for the user to select the job number from a drop down list and then add the information required. When they hit the submit button, it would update that information in the appropriate cell. I can do this in Excel using Visual Basic, but I haven't found this functionality in SmartSheet. And no, an update request is not what I want. When I googled this topic, I get page after page after page of people trying to do the same thing, yet no solutions. Will this functionality be added to SmartSheet? Thank you.