I use Z-Wave and the key for me is I'm not beholden to some external IoT service that is a potential privacy issue, can update firmware without my consent, or simply goes away. I feel I own my Z-Wave network (aka right to repair).

For light switches I use Z-Wave modules that use the wall switch as a low voltage switch to trigger the module to switch the A/C circuit. This way the existing switch acts just as it did before. My family really doesn't notice, yet somehow that porch light is always on around dusk and off by dawn.

I don't use Alexa or the like but as a developer I easily integrate with DiY equivalent.

That last point is probably a key gap generally though -- as a developer this home automation stuff comes easier to me, potentially.