My impression (not interested in pseudo sciences so I haven't looked into this hard) was that Astrology froze before Kepler explains how the planets move, and so the model used by astrologers is just wrong and won't actually tell you what was in the sky when you were born for example?
You don't need Newton (who figured out why they do that) but you do need Kepler or your physical data will be wrong surely? It won't matter because this isn't actually a way to divine the future, but it will be wrong AIUI
Modern ascendant calculations are "correct", in the sense that they'll match what you see in the sky. Apps like AstroMatrix work from NASA data.
As you rightly observed, it doesn't make a difference when it comes to foretelling the future. But it does make a difference if your aim is to make money selling it. The big spenders on these applications often care a great deal about getting the particulars just so.