The role the stars play in it all has its limits, based on G-d’s wisdom.
Some of their functions can be seen with our own eyes, which is a lot of what astrologers depend on. But not all of the influence of the stars can be caught sight of.That’s why astrologers can’t fully read the future 1.The stars’ dominance can always be undone by G-d’s will 2.. As our sages put it, “Let the astrologers, star gazers, and fortune tellers stand and tell you something” (Isaiah 47:13)” – “(they can predict) somethings, but not everything” 3.
Footnotes:
1. See Adir Bamarom p. 235 and Ma’amar Havichuach 108, where Ramchal differentiates between the function of the stars for all appearances and the inner Divine forces behind them prodding them on. Also see Klach Pitchei Chochma 32 (part 1 of Ramchal’s own comments) where he explains the difference between what’s seen and what’s not.
2.See 2:7:3 above.
3. Breishit Rabba 85:2. Also see Hilchot Yesodei Hatorah 10:3 where Rambam differentiates between the vision of astrologers which is limited, and thus often wrong, as opposed to the true vision of prophets.