Preheat the oven to 400°F. While it preheats, prep the fish.
Make the fish: In a small bowl, mix together the dry rub: chili powder, cumin, smoked paprika, garlic powder, and onion powder. Pat the fish dry, then sprinkle it with the 1/2 tablespoon kosher salt and pat it in. Add the seasoning and pat it to cover the fish. Place the fish on a parchment lined baking sheet. Bake for 10 minutes, until tender. Then broil for 2 minutes until the top is lightly browned. When the fish is done, break it with a fork into bite sized pieces. (Try to serve immediately as the fish gathers moisture as it sits.)
Make the sauce: Meanwhile, in a medium bowl, whisk the cilantro, Greek yogurt, mayonnaise, apple cider vinegar, garlic powder, onion powder, cumin, and salt. If necessary depending on the thickness of the yogurt, add a teaspoon or two of water until the sauce is easy to dollop. Refrigerate until serving.
Prep the toppings: Toss the shredded cabbage with a few pinches kosher salt. Open and drain the pico de gallo.
Warm the tortillas: If desired, char the tortillas by placing them on an open gas flame on medium for a few seconds per side, flipping with tongs, until they are slightly blackened and warm. Or warm them according to How to Warm Tortillas.
Serve: Assemble the tacos by topping the tortillas with fish, cabbage, pico de gallo (removed with a fork to drain of excess liquid), and the sauce. Top with additional chopped cilantro and serve.