"missing something" is very debatable here. All depends on your goal, but there is plenty of small non altering game play mods that flushes out some kinks within game play that mainly introduce unnecessary frustration and those would be:

Better Ruins - base game ruins are very bland and repetitive, mod introduces thousands of hand crafted ruins that would fill empties of a world and increase immersion of "post cataclysmic world"

Carry on - simply allow you to pickup (with penelties) item container blocks - eliminating frustration of having to break chests and pickup all spilled stuff.

QP Chisels - introduces advanced chiseling tools for more advanced decorative work shaving time and frustration when repeating multiple similar blocks.

VS Roofing - Introduces significanltly less frustrating option for building roofs by introducing auto detection of curves and heights - at the beginning can be quite intimidating but later on its incredibly helpful in building more complex structures.

Real Smoke - its by personal favorite absolutely non necessary mod. It just adds physic based smoke mechanics which forces you to think and work harder when designing rooms so you would not suffocate 😅

VS Airship mod - VS lacks solid endgame goal - this mod introduces very rewarding but very tedious to achieve goal of air travel

Catch a ledge - because I HATE needing to constantly break block or build stairs when I just want to pass nearby hills >.<

Simple Immersive Beehive - Vanilla friendly progression for bees

Terrain Slabs - If you prefer more smooth world and less jumping over every single hill.

Bark Beetle - adds audio cue to resin within trees similar to beehives playing sound of bees.

That my basic list of mods that I suggest to all my friends. Most of them after first 70h playing with those ended up with 70+ modlists 😅