I do the same thing. I bought music from Amazon for a while. Every now and again I bought some German music from Amazon.de. The purchase works well enough but after that none of my non-German music works in the Amazon player. The Xbox One will simply not let me purchase anything that's not from my region.
The XBox One is an absolute disaster area when it comes to multi-region support. The single most annoying example is that the interface language is linked to the country you're in. For example, living in France, with a French credit card, I can't configure my XBox in ENglish if I want to be able to buy things. I can lie to my XBox and tell it I'm in Australia after having purchased things though, and it will then let me play my games in English, but I will have to switch everything back to French if I want to buy something else.
Why not just use Amazon or Google music and download everything ? Google Music is especially good because it lets you download a .zip with complete album compared to Amazon that only lets you download one song at a time.
I used to buy and rip CDs but it takes time and space and feels really backward.
I have a wall bookshelf which has a corner-to-corner shelf in it for CDs, and another for DVDs. That makes the bookshelf more interesting and gives an otherwise really cold-looking room warmth, without taking up space. As mentioned, Amazon makes it frustrating to buy digital content from another region (although it does work). Google is not an option because I'm one of those people that avoids anything Google, no matter how convenient their products may be.
All of this is very subjective. Your points are well made, nonetheless.
I buy something from another region and download it using Amazon's tool. I then buy something from my own region, and the download tool and player can't download it, saying it's now tied to that other region. It takes a phone call to fix.
Also, I'm constrained by the encoding Amazon gives me.
The CD or DVD just takes all that pain away.