Make the dressing. Whisk together all the ingredients for the herby ranch and season to taste with salt and lots of freshly cracked black pepper. Refrigerate for at least 4 hours as the dressing gets better as it sits.
Marinate the chicken. In a mixing bowl, whisk together the olive oil, garlic powder, onion powder, and smoked paprika with salt and pepper. Add the chicken to the bowl and toss well to coat. Marinate for at least 1 hour, up to 48 hours.
Boil the eggs. Bring a small pot of salted water to a rolling boil. Gently lower the eggs into the water and boil them for 8 minutes. Transfer them to a bowl of ice water and let them cool. Once they're cool, peel and roughly chop them.
Grill the chicken and corn. Preheat an outdoor grill to 400 F. Grill the chicken for 3-5 minutes per side, until cooked through to 165 F. Alternatively, you can grill the chicken indoors in a skillet or on a grill pan until cooked through. At the same time, grill the corn for 6-8 minutes, turning occasionally, until some of the kernels are charred. Let the chicken rest, then cut it into slices. Use a sharp knife to cut the corn kernels off the cob and set them aside.
Assemble the salad. In a large mixing bowl, layer the chopped romaine with the red onion, tomato, corn kernels, bacon, egg, cucumber, avocado, and diced feta. Top with the grilled chicken and drizzle with the herby ranch, as desired. Top with more chopped basil and dill before serving.