Cd has a much larger music selection than ANY digital services.
Well, in some sense, the CD is a digital service as well, performed by the manufacturers to serve digital data conveyed by a physical medium. It is just not online- or internet-based.
digital files are infinitely copyable and backup-able, if only the user takes the bare minimum of care. As such, CD rips, or any digital files, are literally forever. Much unlike a physical format like CD.
The first sentences here are correct, but the latter one mixes up different logical levels because digital information always needs a carrier of some sort, i.e. a physical format and thus doesn't fundamentally differ at all from the stated example of a physical format like a CD.
The only question is which medium is more resilient, reliable, providing what capacity, transmission speeds and access times.
CD rot depends on manufacturing quality. Sometimes it is a real concern, sometimes it is not at all. But it's a problem, long term at least.
While it's true, that when the time coordinate is long enough, not only the survival rate of everyone drops to zero according to "Fight Club", also any physical media will eventually fail, I don't know why this trivial fact tends to get always so stressed in regard of CDs as if that would be a particular minus point of them. In practise, pressed CDs from 1982 pretty much still run more than 42 years later without an error rate exceeding the C1/C2 error correction capabilities in most cases which I consider to be damn remarkable.
Harddrive deterioration is also a real thing.
There you have it, and why wouldn't it be? The - at the end always 'analog' (or neither as in "it just is") - carrier of digital information is subject to the 'imperfect' physical world so only the latter may be preserved endlessly when copied in time as stated correctly in your posting.
My point is: purely digital music is the easiest in the world to keep, play back, and backup. No CD collection or streaming service can compete with the private music enthusiast who takes even the most basic care of his music collection.
That raises the question what "purely digital music" shall be given the preceding arguments. Digital is digital and can't be emphasized.
At the end, any music or data collection has to be stored somewhere, so the only question is what kind of medium one prefers.
In terms of accessibility, storage capacity and data throughput, the CD is without doubt entirely outdated whereas the aspect of reliability deserves a more differentiated analysis. Nonetheless, it is also one of the best and brillant product of its time where many things have been done right.