??? All of Home Assistant is open, with well published and documented APIs. It would be very easy to integrate into Home Assistant. Those are 100+ of Brilliant switches not ordered just for those three projects.
I really like Brilliant controls, but their lack of integration with Home Assistant just meant that two homes and one commercial space we decided to order alternatives to Brilliant because the integration ability was not there.
There is no way that Google, HomeKit, Alexa, etc can keep up with Home Assistant’s wide variety of integrations in the long term. IMO, it is the only viable smart control system out there if you want to build more complex smart homes. For simple residential smart homes, all these options are of course fine…but when you get into more complicated HVAC, ventilation, retrofit to legacy home theaters, etc. all the common systems fail. The only options are totally custom Control4/Crestron or Home Assistant.