How to make a futuristic Sci-Fi setting feel ancient?

My setting is a chronological space opera set in the far future. FTL travel/communication, megastructures, and vast interstellar civilizations are commonplace. Despite the advanced tech I want my setting to also feel ancient. While I know settings like Star Wars do achieve something similar I'm wanting a different vibe. Star Wars feels old, gritty, and lived in but I want something that feels more…