"Smart NeoPixel"

A nice thing about Arduinos is that you're not stuck with the pre-made boards. Since a digiSpark with an 8mm NeoPixel might be "too big", here's a 5050 NeoPixel piggybacked on an ATtiny85 DIP (running the same SW.) a "smart NeoPixel." It still plugs into a socket or protoboard. It's not quite this tiny when running - there's supposed to be a pretty substantial bypass cap, and batteries are sort-of a problem. But I'm pretty happy with it. There's some superglue and Thinking Putty involve for physical security...

Kinda confused here - and that may be because I've not played with "neopixels" before - but...

...what does the addition of the controller gain you (on a per "neopixel" basis) over a bare "neopixel" (note - I am putting the term "neopixel" in quotes because that name is technically an Adafruit brand name for an RGB LED with an integrated WS2812 or WS2811 controller)?

IOW - a "neopixel" already is a "smart" LED - meant to be controlled in a serial bus fashion by a microcontroller on the bus (or something similar). Adding a microcontroller on top (well, under - heh) the already-smart "neopixel" LED doesn't seem to offer much (beyond making it easily pluggable into a breadboard - but a breakout board for the "neopixel" LED itself would do the same, and such breakout boards are already available).

What am I missing here (and I concede that I may be missing something)?

The added controller lets you program whatever color and patterns you want the smallish device to emit, using the convenient libraries. Technically, as shown, it's no more capable than an ordinary RGB LED wired to the same chip, but: the wiring is easier (no resistors, fewer connections) and the SW support is better. (Normally, an advantage of neopixels is that they chain together and make it easy to do patterns. But I'm not using that here.