Let me add a few things the OP:
1) Keep in mind that the ratio of digital/physical only includes games that are available in both formats. Therefore, digital-only games like Hellblade, Sonic Mania, The Witness, aren't included.
2) I never actually said physical games will completely die. I used the word "obsolete". They will still be a small niche, like music vinyls.
Can you point me to where it actually says this?