Preheat oven to 450°. Toss beets with 1 tablespoon oil on foil-lined rimmed baking sheet; season with kosher salt. Roast, tossing once, until skins are charred and beets are tender, 40–50 minutes. Let cool.
Meanwhile, heat 2 tablespoons oil in large skillet over medium-high. Cook radicchio wedges cut sides down until browned, a couple minutes per side. Transfer to serving platter.
Add pomegranate juice to skillet; bring to a boil and cook until thickened and coats back of spoon, about 5 minutes. Stir in vinegar; season with kosher salt.
Tear open beets and arrange around radicchio. Top salad with pomegranate seeds, spoon over with dressing, sprinkle with sea salt, and drizzle with remaining 2 tablespoons oil.