About 70 percent of Ukraine’s population uses Telegram as their main source of news, but the government is worried that the app is being used as a method of disinformation and spying by Russia. They are trying to pivot to apps like Signal instead, but it is difficult to break the habit of such a majority of the country.
Obviously yes, it is catastrophic for security to use windows, macos, android, ios. Anyone trusting this software is a fool.