Brilliant was a Smart Home company who made light switches you could install, replacing your existing ones.
They only offered cloud control and APIs were private — they actively rebuffed any attempt by the community around Home Assistant to better support their product.
No Matter, nor ZigBee or Zwave, so with the shut down they are another IOT device you essentially need to rip out and throw away, this is painful since they were approximately $350 USD each.