So if every single piece of hardware or software followed this one crazy trick the world would be better because some people at a tech company wouldn’t have to field as many support questions?
Margins are already razor thin in hardware, so yeah anything that can be done to reduce your support costs is welcomed.
However, these IoT companies add these features mainly to benefit from selling the acquired data. The users are not asking for this. They're making it difficult for themselves.
I agree. I have support costs too. Which is why every company that sells a product with a hard coded DNS server configured but doesn't advertise said aspect prominently in all advertising, so I can know to avoid their intentionally defective product, should pay me $10000 for the time I wasted buying their product, discovering their product is secretly and intentionally broken, and then return their product.
This is done because the manufacturer’s and public DNS servers are more of a known quantity then you ISPs router and DNS servers. Using pihole is super rare and wouldn’t be worth the effort if it weren’t for the fact that it makes devices more reliable.
Saying that a device is not violating any standards as they "aren't required to accept DNS servers offered by DHCP" is like saying a device is not broken and not violating any standards because "they aren't required to accept IP addresses offered by DHCP." It's a silly to say devices are not required to accept the parameters sent by my DHCP server as such a statement is only correct in the most abstract sense that there is no law that requires a device to adhere to the relevant RFCs for DHCP. On the other hand there are laws, federally and in many states, that only allow you to connect to and use other people's network with their permission and only use their networks within the bounds that they allow.
I don't care about the device manufacturer's opinion of DNS server quality. I own the device and I own the network that the device is connected to and I pay for the uplink between that network and the rest of the internet. There is only one person who can correctly make an assessment as to the correct DNS server for my network and that is me. If a device manufacturer chooses to hard code a different DNS server they are wrong and it is broken and they should tell me so I don't waste my time buying their product and returning it.
Additionally they should advertise this behavior because it is a security vulnerability for my network for their shitty device to be sending my internal names to outside servers to resolve. The names of the devices on my network that I choose not to expose to the internet are no business of anyone else.
E: And I didn't even get into the mess that it would be to try and expose the DNS zones for the RFC 1918 address spaces that everyone is using.
The more convincing narrative is that setting custom DNS decreases ad revenue and cuts into growth.
The same thing that happened each time when DRM servers went offline. Time to buy a new TV :^)
"Sorry, your product is out of warranty, I can redirect you to sales"
On balance, I'd expect Google is be much better about maintaining their DNS uptime than most ISPs.