I had the cracking/flaking issue show up with a Kindle Touch cord. I threw it out & switched over to buying AmazonBasics cables for my devices instead. They seem to much better made than any I've seen being given away with a device (regardless of manufacturer), and I've had no trouble with them over the two years or so I've used them.
As for the older (or newer) Kindles being better quality...no, I don't think so personally. If you were to go back and look at threads around the release time of each device, you'd find every model had more than its share of complaints. This is the nature of Internet forums. Those who are lucky enough to get perfect, long-lived devices generally don't have a need to post as much about them. They're too busy using them!
