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 over 1 thousand in past month.
I can also find a bunch of sellers on Amazon selling VCR and VHS players, but that doesn't mean it's good idea to use VHS tapes and expect them to keep your videos safe in future.
And with strong enough magnets you can easily destroy any information stored on CD, DVD and hard drives.
Third, USB media is more brittle than a HDD hard disk and can be corrupted more easily, thereby making it more susceptible to failure and so on so forth.
There are some exceptions, for example Sandisk ExtremePro that is super fast USB stick that is in fact SSD drive, and they also have microSD format.