Any sufficiently advanced algorithm is indistinguishable from AI.---Michael Paulukonis
According to What are the minimum requirements to call something AI?, there are certain requirements that a program must meet to be called AI.
However, according to that same question, the term AI has become a buzzword that tends to be associated with new technologies, and that certain algorithms may be classified in AI in one era and then dismissed as boring in another era once we understand how the technology works and be able to properly utilize it (example: voice recognition).
Humans are able to build complex algorithms that can engage in behaviors that are not easy to predict (due to emergent complexity). These "sufficiently advanced" algorithms could be mistaken for AI, partly because humans can also engage in behaviors that are not easy to predict. And since AI is a buzzword, humans may be tempted to engage in this self-delusion, in the hopes of taking advantage of the current AI hype.
Eventually, as humanity's understanding of their own "sufficiently advanced algorithms" increase, the temptation to call their algorithms AI diminishes. But this temporary period of mislabeling can still cause damage (in terms of resource misallocation and hype).
What can be done to distinguish a sufficiently advanced algorithm from AI? Is it even possible to do so? Is a sufficiently advanced algorithm, by its very nature, AI?