Every 2016 blocks, Bitcoin looks at how long those blocks actually took vs the 2 week target. If miners found them too fast, difficulty goes up. Too slow, it goes down.

No committee. No vote. Just math checking its own homework.

This is why hashrate can 10x and blocks still come every ~10 minutes. The protocol just adapts.

Block 949,276. Difficulty 132T. Still ticking.