I doing much the same. I have very stable home automation backbone, BTicino BUS system, with its own scenario controller doing most of the automatic stuff. Its basic compared to the openHAB possibilities but its reliable and I don’t tinker with it much.
I use openHAB more as a top level control tool, for visualisation and reporting, and a means to integrate Alexa voice commands and my other home automation devices into one complete experience. Its the icing on the cake and very nice too. Its ability to bring together a miriad of devices is the reason I chose it over other home automation platforms. The end result is impressive and it does some cool things but if it falls over my house automation will continue on without it anyway.