Not to mention, across Toast and InKind and several other modern POS vendors these days, I'm increasingly not signing a paper receipt, instead tapping my card and inputting a tip at a terminal the server has brought to the table or just using my phone. (The receipt gets emailed).
Maybe you're not in the US? (Although my experiences abroad has been that other countries were actually ahead of the curve in terms of tableside electronic POS, and/or that tipping was not a thing.) Is this a problem you personally have been facing?
If you're looking at tracking work expenses, all of a sudden you're up against Expensify, who have receipt scanning apps not at all unlike what you've proposed... and integrations with a whole lot of corporate billing packages.
To answer your question, as a reasonably frequent diner both personally and in business, nobody's done this because personally it's a very uncommon problem that already has some safeguards in place for many, and in most cases could be rectified by a chargeback, or in business, solutions are widely available.