Whisk lime juice, avocado oil, chili powder, cumin, garlic powder, salt, and pepper in a bowl. Add chicken thighs, coat, cover, and chill for 15–30 minutes.
Heat skillet over medium-high. Cook marinated thighs 8–10 mins per side until done. Rest 5 mins, then slice.
Combine corn, red onion, sour cream, mayo, Cotija cheese, chili powder, salt, pepper, and lime in a bowl. Stir to mix.
Reheat 4 cups jasmine rice in microwave with water splash or in a pan until warm and fluffy.
Divide rice into four bowls. Top with sliced chicken and street corn mixture. Garnish with extra Cotija, cilantro, and lime wedges.
Drizzle with sour cream and sprinkle with Tajín or chili powder if desired. Serve warm with lime wedges.