Cell Broadcast is part of GSM since 1995. It's the phone manufacturers' fault that it doesn't work properly. Other countries have been using it for years now.
SMS also gets ignored all the time since spam and fraud over it is rampant nowadays.
My mobil phone number has existed since the beginning of time. It is listed in the public phone book. It was on my private web site for a long time. I've never not handed it over to any sign-up that needed a phone number.
I cannot remeber receiving any spam and/or fraud SMS, ever.
Maybe I'm just lucky, or the report of huge amounts of spam/fraud SMS is elsewhere, but not in Germany.
SMS also gets ignored all the time since spam and fraud over it is rampant nowadays.