I find the worst point with all of them is near the end of the cable where it hits the connector.
If I think a given cable will get used regularly, I now just grab a pack of Sugru and add my own strain relief at that point. I find it helps a lot, but on one cable (and I forget which of the 28934774 cables I own it was...) it just moved the fray point from where it would naturally occur near the connector to the point where the Sugru tapered off.
I think the only other thing a person could do is both add their own silicone strain relief and maybe dunk the cable a few times in dip-it vinyl coating to armor the cable further.
It would be nice if someone would figure out that high-quality cables were desirable and make USB versions of welding cable with thick, high-flex EPDM jackets. I could definitely use a couple of Ethernet cables like this.