At least part of it has to be this. I, for one, immediately hang up and blocklist anyone who calls from an unknown number and declares to represent an utility provider. They do not get a chance to explain. And it could be worse; I know several people who just don't answer to unknown numbers, period.
I am well aware that I might be missing on some relevant communication this way, but what else am I supposed to do? I get several such calls every day, and determining whether they are genuine takes a significant effort - and 99.99% of times they are either spam or scammers or both.
If my provider really needs to tell me something, they'll have to contact me via snail mail, or an email that I can recognize as genuine.
Or, even better, phone companies should take action to stop unsolicited calls for real, and then they may get to use the medium for its actual purpose again.