This is exactly what HA has been for me. I had several smart bulbs on Apple HomeKit which were… unreliable to say the least. After switching everything to Home Assistant as the main brains, it’s been rock solid, and a LOT faster. I even have an Apple TV which should have helped HomeKit be better.
You can still use Apple’s automations to do stuff in HomeKit. I mean all the rooms & devices “just show up” in Apple HomeKit seamlessly. “Siri, bedroom off” works perfectly with no setup, for example.
Apple home is ok, but automations / iOS shortcuts are unfortunately extremely difficult to write unless they’re very simple. As a technical user, it’s nice to have the option to do something deeper if I want. But the biggest problem for me was the reliability, even for bulbs allegedly fully supported by HomeKit.
I originally only set HA up to bridge in non-homekit devices (like my Govee LEDs), which is also a good use case for HA.
I’ve been fiddling with my smart home less than ever now that HA is set up.