There is machine readable and consistently machine readable in a limited time under non-ideal lighting conditions with part of the code obscured using only cheap cameras and processors. Barcodes didn't just stop having a purpose in 2025.
Another common hangup is a legible font needs to unambiguously distinguish between lowercase eL (l), capital eye (I), the number one (1), and the pipe symbol (|), or at least for instance only deal with capital letters and numbers.
