Create Aeronautics, Apotheosis, Minecolonies, Twilight Forest, biome mods, some structure mods, and some artifact mods sprinkled in to keep things interesting. Oh, and also quality of life. Lots of QoL.
The mod count isn't low, but many of the included mods only add very subtle improvements to the base game. You'll find mods that in my opinion make the game much more beautiful, without tarnishing the core look and feel of minecraft, or add fun separate gameplay loops that don't dilute the core experience.
Enjoy <3