Here is a ranking of the Star Wars films' relative popularity on Netflix. The list is, from most rented to least:
Revenge of the Sith
A New Hope
Attack of the Clones
The Phantom Menace
The Empire Strikes Back
Return of the Jedi
I suspect the myth that 'once the prequels sunk in it was universally decided that they were rubbish' is just that - a myth.
This list also suggests what I have subjectively experienced: that, regardless of actual quality, the prequels have a higher 'rewatch' value. There's more to see a second or third time, because of the more lavish visual effects and the stories having more POVs.