Members of Parliament reacted with incomprehension to a warning message from the NL-Alert system that was sent to people in Noord-Holland about the severe storm that struck on Wednesday. People were directed to Twitter for news and updates about the storm, while that medium has been inaccessible to people without an account since last weekend.
See, this is where you’re right, but very wrong. You are correct in that text and email are privately controlled, but they arent comparable to Twitter - in scale, composition and ownership.
Email and SMS are open protocols that are not controlled by any one group, and the systems are all interoperable and open standards control how they work. Twitter is a privately controlled platform with no visibility into how it works, no interoperability with other services. The better comparison would be email and SMS to the fediverse.
That goes back to openness, standardization, and interoperability of email/SMS. Because of all those items, no one person can disrupt communication because there’s no central control.