Personally I ended up crafting my own 100GB Blurays, all you need is a bluray recorder, and a printer capable of doing that. In the end I mostly keep two SSD drives in sync but this great as a 2nd backup type. I've been busy with other things but some amazing things like MAME look beautifully properly backed up on a bookshelf.
Download the offline installer of any of your games on GOG, save it to a disc and it's yours forever.
You don't need a storefront's permission to play what you bought.