I've never had HA itself fail. I've had it installed for 10 years and the only true failures were hardware (server, iot devices) or my own config mistakes.

If you choose your hardware wisely, it's incredibly reliable. Most of my house is automated and I all I've done with it in the past year is add a few devices.

I will admit that low (or zero) maintenance is easier to accomplish if you know your way around a little bit.

I used HA for about a decade without so much as a hiccup.

What makes you think it’s a toy?