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.
In the end everything need some extra layers of bureaucracy to comply with the laws or is simply not done. And the funny part is that many think this is how it works in other countries too.
Germany went so far as to request a change in EU legislation that required cell broadcast to be used.
After the last warning test day was disastrous, it was decided to implement it after all.
It was a complete failure on all fronts where the federal and state governments then tried to blame part-time mayors afterwards for not being experts in catastrophe management.
This isn't held back by the bigger industries but by entrenched boundaries of responsibilities in the administration (defined in the regulations), data protection, and over-engineering.
Latest example: Warning the population. Instead of simply sending SMS to all active phones in an area, it has to be cell broadcast, which doesn't work on old phones. The reason seems to be (information in media is... limited) that sending SMS would not provide a way to send a cancel/warning-end message. That's only possible with cell broadcast. And that hasn't been used so far due to data protection concerns (there's a list of phones that have been warned, i.e. were in the affected area).
We cannot solve things the simple way.