I’ll Rule the Entire Universe with a Fleet!

Hard Science Fiction That Goes Cosmic in Scale: No Mecha or Monsters, It Has to Be Hard Sci-Fi

It has to be grounded in reality or have a unique theoretical framework, like "The Galactic Empire" or "The Three-Body Problem"... but... it needs to have that web-novel feel... Aaaah, I’m so torn (๑•́ ₃ •̀๑). Cuties, please stop recommending "The Three-Body Problem"! I’ve definitely read a masterpiece like that.

Pure Starship Battles, No Mecha or Ground Wars

Looking for books like "Interstellar Lord: My Starships Are a Little Too Numerous".

Space, Empires, and Fleets Blasting Each Other, No Xuanhuan

Looking for books similar to "I’m a Level Two Civilization, So Having a Two-Dimensional Foil Makes Perfect Sense (Deep Space Cataclysm)".

Hard Sci-Fi, Interstellar Travel or Drifting, and Alien Civilizations

I don't like stories that are constantly at war, fighting from beginning to end, from the Solar System all the way to the Milky Way. I prefer nuanced portrayals of alien societies and storylines, as if observing another civilization.

Please Recommend Hard Sci-Fi with a Tech Tree and Battleship Showdowns

No System or cultivation. I want pure sci-fi.

Looking for Good Novels About Interstellar War, Rated Above 9.0

Stories Where the Protagonist Returns to Earth with a Fleet of Starships and Shows Off His Power

Any books where the protagonist starts out with a bunch of newly acquired stuff, returns to Earth, then shows off their high-tech weapons and gives everyone a good thrashing? Please, I'm begging you!