It’s sustainable at $1/month at current costs, but those costs will go up over time. The subscription price could be raised accordingly but they can’t go back and ask for an inflation adjustment from people who bought it.
Amazon may not be going away tomorrow, but they have form for disallowing redownloads of old ebook purchases. If you dared to buy ebooks from them pre-Kindle, you can't access them anymore. If you hold onto your Kindle devices for too long instead of replacing them with a newer model, you can't access your old books that aren't already downloaded until you buy a new device.
For now, Sony has no issues with people redownloading PS3 games. Or PSP games onto a Vita - not sure if you can still download onto an original PSP. They'll probably jump on the Amazon revoke-download train eventually, though.
Sony wouldn’t see any benefit from switching to game key discs. Nintendo introduced them to save on manufacturing costs, but game key discs wouldn’t give Sony any additional market or reduce costs any; they’d only shrink the physical market further.
It seems trivially simple until you have two dependencies with conflicting exact version requirements... So I don't think you can get rid of floating versions entirely. They did add NPM-style lockfiles for PackageReference, but currently not mandatory.
The version numbers for BindingRedirects are orthogonal to the package versions. You can have multiple package versions use the same AssemblyVersion so that applications don't need to create BindingRedirects. (e.g. Newtonsoft.Json - 13.0.0, and 13.0.1 in NuGet are both 13.0.0.0 for binding redirect purposes) And .NET Core/5+ don't need BindingRedirects at all!
But just the dependency list isn't sufficient to pick a specific version, thanks to dependency ranges. If Package A depends on Package B >= 1.0, and Package B has v1.0 and v1.1 available, it will use v1.0. But if Package B suddenly unlists v1.0, then future restores will change to v1.1.
NuGet is lock-by-default for the parent package, but with the move from packages.config to <PackageReference> it's no longer lock-by-default for dependencies.
Amazon.jp does ship everywhere, but their international items use a separate warehouse, and sometimes items are only stocked in the domestic one(s) and are unavailable for international shipping.