>>linker+(OP)
Since I don't see it mentioned here I would like to suggest z-wave (protocol) and the accompanying ecosystem as an alternative.
I have multiple lights, power plugs and sensors operating on z-wave being controlled by Home Assistant. None of these require me to log into a third party app or service.
>>MrDres+hd
I've noticed a lot of z-wave adopters seem to be shifting towards zigbee. I guess because it is closer to thread and matter? Some devices seem to be upgradeable for that too.