Infinite Regress & the perennial first cause
The fact that PI remaining abstract yet embedded, but not fully, by fact of impossibility in the real world in the form of the circle highlights a very profound idea of such an abstraction namely that of a never ending non-repeating number.
In a sense, whilst Pi was known to the Greeks, it is actually a Greek letter in their alphabet, they never truly realised the implications of such a number, even Archimedean approaches never went more than two decimal places, so it’s real infinite nature was not readily apparent.
Though PI itself remaining an abstract with imperfect manifestation of itself in the form of a circle perhaps only comes to our understanding by fact of producing the approximation of such a shape.
PI even has a starting value. 3.14 somewhat implying that if it does have a starting value does infinity too?
I believe, again, that this line of reasoning is incorrect, even though by granting it such a concrete starting value (which is always an approximation), by the fact that this value itself never finishes, let’s it remain in the realm of the abstract and pure mathematics.