One optimization I'm surprised hasn't made it to Minecraft yet is parts of chunks deep below ground will sometimes render before blocks closest to the player or at least closest to the ground that the player should be able to see. I would think if you're at ground level looking around, it should prioritize loading blocks that are most likely to block vision for the player.
Minecraft is horribly under-optimized, but unfortunately a lot of the deeply architectural things might be impossible to touch without breaking something for the more technical players. (Check out Docm77 or TangoTek, they're really pushing the game to the absolute limits.)
If you don't mind clientside mods, there are a few dedicated to optimizations, including rendering: sodium, lithium, phosphor, optifine. I'd recommend PrismLauncher and Fabric for managing/loading the mods.
