That’s exactly the problem. Each company will have its own invoice “standard” which means in order to make this work, you are proposing some convoluted setup per each supplier which also needs to be maintained. You will spend more time maintaining such a system than just manually entering that one invoice per month. That’s why nobody is doing it that way and most likely never will.
If there are many invoices, then usually businesses will agree on some electronic standard so they will send each other invoices which can be read by machine without any upfront setup. Small businesses rarely deal with this issue though so it’s not really such a big deal.
If Manager were to support this, it wouldn’t be OCR. It would be something more reliable such as QR codes which will embed relevant data or similar.