Interesting. In my over decade of MacBook ownership (about 5 or 6 MacBooks in total across my personal, work and wife's devices), I've never had a single problem with fraying cords.
https://www.thrillist.com/tech/nation/why-apple-hasnt-fixed-...
The worst thing that happened was one of the dell chargers started making a quiet beeping/buzzing sound - I read it was to do with the components coming lose inside and the sound was caused by the switching supply. I decided out of choice to get another, although there was nothing actually wrong with it as far as performance goes.