Taco Bell has never, ever been good. Of the chains Del Taco was okay, Naugles was too. Then came the fresh taco places like La Salsa, Sharkey's and Baja Fresh followed by the fish taco places, Rubios and Wahoo's, then Chipotle.
The best are always the hole-in-the-wall one offs. The are very small local chains like King Taco and then the taco trucks.
Dunkin Donuts was in CA, but Winchell's was dominant. Then CA went on a health kick and donuts were out. Winchell's & Dunkin' completely disappeared and donut shops became individually owned shops by Vietnamese & Chinese immigrants. Maybe 15 years ago Krispy Kreme came to CA and nothing is as good as Krispy Kreme, especially when they are hot.
Hawthorne Mall went away because it couldn't compete with Del Amo and South Bay Galleria. It wasn't the collapse of the middle class, it was the growing affluence of the South Bay that doomed Hawthorne. Who wanted to go to JC Penny & Montgomery Ward?
You want to explore fascinating So Cal past.... explore Pacific Ocean Park, Marineland, Busch Gardens and the Z-boys.