I would hope that there is little disagreement [here] that as much local control as possible when the internet drops offline is a better design architecture. My design objectives with home automation ensure that the original get up and turn the light on/off via the same way you did it 5 years ago is sustained. This does take some work, but keeps the household from taking any position on ‘get rid of it’ because I softly remind them they could always get up and turn the light on/off - and the broken ‘thing’ is really a convenience. Moving to HA would be another effort in this similar direction. IMHO.
However, my true objectives in IoT (and hopefully some others here) are around home artificial intelligence such as Alexa (Conversational AI). I am not seeing HA solving that problem - so I personally am not in a rush to jump off ST and invent my own similar wheel, but respect those of you that do.