I don't think it's rigged, but I do find it kind of...less interesting seeing (for the most part) the same top 3 every single week. And that's coming from someone whose favorite is Gabby.
Rigged isn't the right word, but predictable might be a bit more fitting. Seeing people like Shangela and Daniel, and even Jordin, move up the ranks each time has been great! Even Trevor getting such a high score on Halloween!
But, barring any unforeseen slip-ups tomorrow, anyone could've easily predicted that Charli, Gabby and Wayne would be in the finale with the rest fighting for the 4th spot.
I don't know if past seasons had more parity.
I also think people confuse "rigging" with "bias" and not being truly objective, on the judges' part.