They clearly percieved it within the system. The Ramabm goes on as everyone knows and says only later false prophets took them away from Hashem, they remembered who they ultimately were serving, just they had an intemidiary. An I termediary who was closer to Hashem, who if they honored also honerd Hashem ect..
The mistake they made was that Hashem never told us to worship the stars, while Hashem did tell us to cling to Torah scholars, and clinging to Torah scholars does increase our service of Hashem. On a simple level, the Torah scholar teaches us Torah and tells us how to do Mitzvos. On a deeper level, he inspires us to serve Hashem, and on an even deeper level, by teaching us פנימיות התורה he inspires us to serve Hashem with a Chayus, with דחילו ורחימו. In other words, the entire Tachlis of connecting to a Talmid Chacham is so that he’ll guide us in serving Hashem. In contrast, the stars said “you can’t serve Hashem. He’s too lofty. Serve me instead and I’ll take care of the rest”.