Doesn't Android or CarbonOS just get its signal strength information from the Qualcomm baseband OS? It's a second OS always running on your phone that you can't do much about.
The baseband OS could be lying about signal strength to your phone OS.
The baseband OS could be lying about signal strength to your phone OS.
So even if the baseband didn't lie (which is one mechanism), the carriers can control the thresholds used on their network.
So my question was - I don't have any of that stuff on my phone, with a custom rooted rom, and those services disabled/removed. Simple test now - if I set my phone to 2G, it connects to 2G with full bars, and says 2G. If I set it to LTE, it says LTE and displays 1 bar. Also, every time I reboot the phone, it pop us "carrier config failed."
This makes me believe this likely applies to phones bought from a carrier and not re-flashed. The fact is, if you for some reason buy a phone from a carrier, you are buying into their ecosystem, and for people like that - most people, this 5G icon is what they want, because to them it means faster than the 4G icon on that phone, so I don't see an issue here.
They're mostly mundane things like 'should we believe the language specified in the sim card' or 'what max MTU should be used on this network', but there are also more sensitive things like 'what types of tethering to allow' or 'should we allow the user to manually select which network to connect to while roaming.