Lol. Bullshit to quality plastic lenses last that long. I mean sure, if you never drop them and baby the heck out of them.
The hardest clear plastic isn’t remotely close to being as hard as glass or sapphire.
As for the shatter thing, often glass lenses will have a plastic layer on the eyes side of the lenses that prevents shards. This does mean that the inside of your glasses will scratch easier than the outside, but the outside is what always gets abuse.
Nothing proprietary. It’s just not easy to find a cord that doesn’t have the big bump that will be in your way for a ground.