I share your pain. I also have a collection of cables, most of which are genuine but some of which (like my beloved 3m cables) are of unknown provenance. I have had all of my aftermarket 3m cables silently rejected by iOS 13, while continuing to work perfectly with devices that are still running iOS 12. One of my genuine Apple cables was similarly rejected, and I plan to visit Apple when I have a chance to ask about it. My HDMI and VGA adapters are genuine and still work, though others here are complaining of genuine adapters failing.
The Lightning interface is a proprietary standard, which Apple licenses to parties that pay for the privilege. In exchange for the license fees, these companies are instructed in the tolerances and secret inner workings of the interface. Even so, some older cables and adapters fall out of tolerance over time or fail simply because of manufacturing variations. With iOS 13, Apple has significantly tightened the tolerance as to what interface devices can still work with our iPhones and iPads.
I plan to ask a Genius why my new-looking genuine cable has stopped working under iOS 13. I wonder how many other customers have already asked the same question.