I'm also in CA and lived on Arizona for most of my teens and early 20s. Never saw this pricing. I would have remembered it, especially during the skint college years. It's always been a dollar. At best you'd see 2 for 1 deals.
It sounds like you live in a heavily subsidized market - probably best not to try to draw generalizations about inflation from your specific circumstances, they are atypical.
I think the 99c price was originally for convenience stores because there were sales of 5 for $2 at Walgreens in 2018.