This question of mine was recently put on hold for being off-topic.
This is despite the fact that:
I made it clear and unambiguous about what I was looking for and wasn't looking for in the body of the question
What I was looking for - the best/highest (i.e. highest) compression ratio - is not a subjective thing, but something that can be objectively determined by observation of an audio codec, and is frequently measured by benchmarks, some of which have already been conducted
An additional objection to the question seemed to be that the question could get outdated, but isn't this true of a vast portion, if not the majority, of questions on the Stack Exchange network? The vast majority of everything on this site will be outdated at some point, and many already likely are - technology simply moves too fast to create a repository of knowledge that is both useful (i.e. current) and future-proof.
What's for certain is that the landscape of lossless audio codecs changes far less frequently than that of lossy ones, for example (FLAC has existed since at least 2001).