Aside from scratch, finding device to read/play it shouldn't be hard since you could use any DVD/BD reader. I expect few company will continue to make DVD/BD reader in the future.
Nobody is making devices like that anymore, except maybe in North Korea, they are probably still making VHS players also. 
You can't find cd players on computers, laptops, in cars and I don't remember the last time I, or someone else I know, used a CD disc for anything.
In theory they can work in future, same as gramophones work to play music.
It's true almost all devices doesn't include DVD player. But there are some company make and sell external DVD reader. Amazon even claim one of the DVD reader sold 1K+ in past month.
