No question that people have experienced stability issues when using a Raspberry Pi … regardless of what’s running on it. An RPi doesn’t need to run Home Assistant or openHAB to experience problems. Just look through the Raspberry Pi’s community forum for examples of that. In fact, the causes for instability were first raised, and resolved, by the RPi community.
… but maybe I’ll burn another three SD cards. I could get another power supply, but I’m already using the official supply (as recommended).
Think about what you did here. You replaced three SD cards in short order yet never questioned the integrity of the power supply. In fact, you’re still defending it because it’s the “official supply”. Perhaps it’s a defective official supply?
The costs of that quickly escalate, with no real reason for me to expect a stable system will come out of that.
I can’t speak for your situation but I’ve purchased official RPi power supplies for CDN$11 and a 16GB microSD card set me back CDN$10. If you consider these costs to be prohibitive, I recommend you stop what you’re doing and quit home automation. This hobby only gets more expensive. Plus spending time and money to test/fix things is often part of the landscape (especially your time when you hitch your wagon to an open-source home automation software like openHAB or Home Assistant).
It would be better if the developers could perhaps look at a system that boots the pi from an SD card and operates from a usb stick or ssd drive, as openHAS seems to be able to do.
This ability is completely separate from the home automation software (whether Home Assistant or openHAB or something else). Also, it’s convenience feature found in the openHABian version of openHAB (a shell script called by openhabian-config) and not an innate ability of openHAB.
I just do not have confidence in the ‘HA on the Pi’ concept as it currently exists.
Based on what you’ve experienced, I don’t doubt it; I’d feel the same way as well. After doing some research, I’d learn that it had nothing to do with Home Assistant and everything to do with providing the RPi with a clean, uninterrupted supply of at least 5.1 VDC and 2.5 Amps. Given that I had just lost three SD cards, from different vendors, I’d become suspicious of the power supply and replace it with another. If that didn’t fix it, rather than replace the RPi, I’d just choose a speedier platform. But that’s me.
FWIW, I run Home Assistant on a (free) ten-year old netbook.