At least there's EU legislation that's slowly improving as well ensuring longer term warranties and the like. I hope that for household appliances like aircon or solar panels this warranty or support is set to its expected lifetime of 15-20 years. In this case, it should be mandatory that the control system can be easily swapped out by an aftermarket replacement, just like central heating thermostats are.

(in fact, replacing basic central heating thermostats with a tablet device has been very successful for one energy company in my country, see https://www.eneco.nl/energieproducten/toon-thermostaat/; it wouldn't have been possible if the thermostat data thing was some complicated / encrypted nonsense)

My own aircons are just simple individual items that are interchangeable between rooms.

There is no single control for the whole house but on the other hand I never let it run when I am away and I am never in 2 rooms at the same time so I just close the door so I only have to keep one room cool. I fail to see the need of an aircon I could control remotely with a smartphone or any smart bullshit system that control every room at the same time. And I think if I ever needed that I would probably just control the individual aircon via small esp32 with irtransmitter driven by a home server. That way the individual remotes would still be usable in case of an individual failure.

It's that golden hour where AU/NZ are up, Californian nerds are up and chilling and EU/UK are getting their first (or second) dose of caffeine. Just missing our East-Coast buddies :-)