Sure, with years the pretense became increasingly transparent -- and of course, already in the time of Caesar, it was clear to any informed observer that things were very different from the heyday of the republican institutions. Still, I'm sure a second-century Roman would have been offended if one were to suggest that the proud republican "SPQR" inscriptions on public buildings and military standards were just a hypocritical sham, even if that claim would have been more or less correct.

Moreover, the imperial succession is one issue where it seems like the need to maintain the pretense had serious practical implications, since it was impossible to legislate clear succession rules that would recognize the imperial office as hereditary. In this regard, as much as the republican institutions had become increasingly irrelevant from Augustus on, there was still a deep and fundamental difference from explicit hereditary monarchies such as the Parthian Empire.