I buy most of my games on GOG, I don't get disks yet those games are mine, if GOG disappeared tomorrow I would still own them and could still play them (given I keep backups of installers).

I never had a console so I don't know how it works, but if Sony ever decided that to play your disks you need an online connection they control, having disks won't help you at all.

We need to fight the right to ownership, that doesn't depend on having disks.