The ability to use Signal as the default text messaging app has been removed as this was a bad compromise – texts can’t receive the same high level of protection as real Signal messages.
Another problem: Sending SMS is not free with all rates. As a result, some users have to incur additional costs at the end of the month – it’s confusing.
However, the Android feature will not be deactivated immediately, but gradually removed over several months. This gives you several months to switch to another SMS app and export your messages. You will remember this regularly.