That's not how the invoices I receive or send are. They are real invoices with specification, sum to be paid, who to pay it to and date to pay. So let's take a bog-standard example: Your phone bill. Get the invoice in your e-mail, see what amount they want, log in to the bank, select them as the recipient, fill in the sum and paste the reference number. Assuming you're saving recipients in your online bank.

There's nothing slow or archaic about that, at least I haven't noticed that after a few thousand invoices sent and received by e-mail. With modern banks you can even make batch payment of invoices by uploading a csv file.