Your router looks at the protocols and decides who gets priority when sending or dropping packets. Your ISP does it. Etc.
The reason to leave it up to the end user is because the manufacturer can’t know what a class of device truly represents:
My rPi might be monitoring temperature in the boiler room so either the rPi can report itself as a priority device (current situation) or we need some way to know ahead of time “this temperature sensor monitors boilers” and “this temperature sensor monitors back door gardens”.
https://en.wikipedia.org/wiki/Quality_of_service
Same thing with permissions. My firewall is aware my computers and my IOT are different classes of things because I put them on different VLANs. There’s rules about who can talk to who and what they can say.
https://en.wikipedia.org/wiki/Virtual_LAN
It could all be done better - my point is you have the right idea because it already exists (to various degrees).
Lightbulbs live on a different part of the network than your bathroom OnlyFans setup, which you should probably use Ethernet for.
The lightbulb doesn’t have a way to plug itself into the OF filming rig, no matter how much it lies about who it is or what it does.
That would be a mirage anyway. With Nest thermostat's secret microphone, the various smart TVs with hidden cameras, and universal police access to video footage collected by the Ring doorbell network, it has become clear one can't assume any particular device isn't sensing everything in its vicinity. Cell network connections are expensive at scale, but that is due to oligopoly rent-seeking, not technical restrictions. The MNOs are pretending that it's even physically possible for them to own 5g, but it isn't. Connecting around rather than through wifi will become common for IoThings.
I also think separate VLANs could be better (setup is a mess), but using them is pretty easy: you just connect the device to the right VLAN at setup. All of my wall sockets are IOTnet and they have their own AP. I think a big area of improvement is making it easier to provide different VLANs with different DNS.
It’s not perfect, but it is better (owned device can’t access other trust domains; can have firewall rules enforced).
I agree it all could be better and we need regulation around disclosing sensors in IOT devices (eg, Nest should be legally obligated to disclose microphones) or IOT gossip protocols.
If I were in charge of administering MAC/IP/etc addresses that all the proliferating billions of devices were starting to overlap and become a huge noisy pond of traffic and vulnerability, one thing I might do is create classes of devices and different privileges to them.
So instead of every device, from the most important supercomputer/network superhub, down to dumb refrigerator on wifi, having equal priority and "must be listened to" traffic, there would be tiers of who is allowed to take up what bandwidth, assert what privileges, etc.
Otherwise, with the coming storm of devices it will truly be like a shouting match with every device having equal volume and possibility for being a risk to every other device. Of course in some ways a Raspberry Pi can act like a superhub in some respects, so I realize there's challenges on who would decide and how to implement many layers of detail.
But is there any merit to this concept?