Remove seabass fillets from refrigerator 15 minutes before cooking. Pat completely dry with paper towels, especially the skin side.
Season both sides of the seabass generously with sea salt and black pepper.
Heat a large stainless steel or cast-iron skillet over medium-high heat for 2-3 minutes. Add olive oil and swirl to coat.
Place seabass fillets skin-side down in the pan. Press gently with a spatula for 30 seconds to prevent curling.
Cook skin-side down without moving for 4-5 minutes until skin is deep golden and crispy.
Flip fillets carefully. Add butter, smashed garlic, and thyme sprigs. Tilt pan and baste fish with melted butter for 2 minutes.
Squeeze lemon juice over fillets and continue basting for another minute until fish is just cooked through and opaque.
Remove from heat immediately. Transfer to serving plates, spoon butter sauce over top, and serve with lemon wedges.
Notes
For the crispiest skin, ensure the fillets are completely dry before cooking. Don't flip the fish until the skin releases easily from the pan. The fish will continue cooking after removing from heat, so don't overcook.