Until there are proper standards that we can rely on to last for decades plus for automatable home devices in general, Home Assistant will never be truly self-sustaining. Almost all of its integrations rely on unofficial API access, those APIs change often enough to requiring patching etc. Finding a cheap reliable machine to just run Home Assistant has never been the problem either.
Home Assistant doesn't try to solve the elephant in the room: the complete lack of any standards in the industry, instead it tries to patch over it through regular software updates to keep everything working together.
No matter how good you have Home Assistant today, you are just one bad release or API change from any of the hundreds of smarthome product vendors breaking it - it is completely outwith your control. It doesn't happen super often, but it's often enough that I'd think someone a little silly to include it as part of a home sale process. Almost zero of HomeAssistants integrations are supported by the vendor, some vendors are even actively hostile towards efforts to use their APIs in HomeAssistant.
I'm secretly hopeful that the new standard, Matter, finally solves some of this for the long term, especially with Google/Apple buy in, but will probably be years before we see Matter devices hit mass market:
Still, some manufacturers like Lutron makes some nice switches however their cloud connectivity is not something I wish to keep a dependency on for the initial setup. There's simply no reason to make it mandatory.
Another piece of useful gear that is being discontinued is the Logitech Harmony Hubs... no replacement really, and the existing gear will be supported for an unknown period of time. Would be a great candidate to open source.
I am close to adding an iot wifi access point that can remain with the home. All gear connects to it and then up to whatever internet is present.
My HA currently runs in a vm but seeing the fanless devices (or laptops) is encouraging. Chrome books with 8 gb of ram seem like a good candidate to become a server appliance.
Add to it a few tablets and it’s not so bad. Documentation can go a long way as well even if it is for tenants.
The home assistant blue or yellow device is also intriguing for that reason. If it had a touchscreen built onto it it would be one step closer to being self sustained.