That's the thing though: most IoT devices shouldn't be Internet-connected, and most definitely should not depend on a vendor cloud (or increasingly, a cloud of a different vendor that sold white-label IoT solution to the "vendor" you you bought the device from). It's an unnecessary limitation, a combination of laziness (going over cloud is easier than figuring out local-first and standardizing on some VPN solution) and abusive business (the cloud on the other side of the world is holding your Internet-connected air conditioner hostage, better play nice).

If brakes are not Internet-connected, that's mostly because they were established before Internet - and given the trends in car manufacturing in general, it's only a matter of time.

(In some sense, we're already there - if you have cloud-connected self-driving, and that self-driving can override your command to apply brakes, then your brakes are de-facto Internet-connected, even if connectivity isn't a hard dependency in all cases just yet.)