I wonder if you had a counterfeit Magsafe adapter? They commonly get shipped with used Macbooks, and get quite a bit hotter than their genuine counterparts.
I have personally preferred the Magsafe adapters ever since I had a USB-C powered Macbook slide off my bed by accident. It didn't fall far, but it landed right on the power cable and damaged both the USB port and the cable.
Understandably, Macbooks are not designed to withstand any sort of drops, but I'm positive that the Magsafe of my 2015 MBP would have popped out, and the body of the PC would have been fine.
I never had any cords fray ever on any product I ever owned.
Except for basically every single Apple product I ever got that had one of those stupid white cords no matter how gently I treated it. I've never bought anything Apple related from somewhere other than Apple and have been buying Apple products since the first iPod with the physical moveable wheel.
I think within the last few years they finally changed how they made the cords. My replacement Apple brick for my Macbook pro still looks filthy after a couple years of use, but has surprisingly not started fraying.
Almost half of my Apple cords are frayed, in the same spot, right next to their poor excuse for strain relief. Apple has a chronic problem with proper strain relief, and seem unwilling to fix it. Every other cord manufacturer on Earth has solved this problem with designs like this: [1]. Why Apple won't follow suit is beyond me. Maybe the appearance of it offends the sensitivities of one of their ID artists.
I have personally preferred the Magsafe adapters ever since I had a USB-C powered Macbook slide off my bed by accident. It didn't fall far, but it landed right on the power cable and damaged both the USB port and the cable.
Understandably, Macbooks are not designed to withstand any sort of drops, but I'm positive that the Magsafe of my 2015 MBP would have popped out, and the body of the PC would have been fine.