Make the slaw: In a bowl, toss cabbage, red onion, jalapeño, and cilantro with lime juice, olive oil, and a pinch of salt. Let it sit while you prep the shrimp so it softens slightly and absorbs the flavors.
Mix the crema: Stir together Greek yogurt, mayonnaise (if using), lime juice, honey, garlic, and salt.
Adjust lime or salt to taste. Set aside.
Season the shrimp: Pat the shrimp dry. In a bowl, combine olive oil, chili powder, cumin, smoked paprika, cayenne, garlic powder, salt, pepper, lime zest, and lime juice.
Toss shrimp to coat evenly.
Cook the shrimp: Heat a large nonstick skillet over medium-high. Add shrimp in a single layer. Cook 1–2 minutes per side until pink and just opaque.
Do not overcook. Remove from heat.
Warm the tortillas: Heat tortillas in a dry skillet 30 seconds per side or wrap in a damp paper towel and microwave for 20–30 seconds until pliable.
Assemble the tacos: Add a small handful of slaw to each tortilla. Top with shrimp, a drizzle of crema, and avocado slices.
Finish with cilantro, radishes, and a squeeze of lime.
Serve immediately: Enjoy while the tortillas are warm and the shrimp are juicy.