> And as it is today the "public" has no reason/incentive in switching to it and that naturally keeps the "non-technical public" away from it.

I know plenty of non-technical users on Signal. Based on news reports, it's used widely by activists. I see journalists advertising their Signal contact information for tips. It's recommended government-wide in the US by CISA and is pre-installed on US intelligence community computers, including in the CIA.