Eero has acted on its promise of supporting HomeKit for Routers. You can now add any Eero, Eero Pro or Eero Beacon device running eeroOS 3.18.0 (or later) to Apple's Home app, letting the mesh WiFi routers firewall your smart home devices so that a vulnerability in one doesn't compromise your entire local network. You can allow gadgets to communicate automatically with the devices their manufacturers approve, limit them to HomeKit or remove all restrictions if necessary.
It's not surprising that Eero would be one of the earliest router makers to support HomeKit. Apple has a few key tie-ins with Eero's parent Amazon, including support for Apple Music on Alexa devices and Apple TV+ on Fire TV hardware. Even so, this is a big move. If you live in an Apple-centric household, this might be as close as you get to an official HomeKit-friendly solution with AirPort still out of the picture.