One WhatsApp group I'm in considered moving to Signal but they seem to have dropped the idea now. I think their concerns were as much anti-monopolistic as security and as Signal is, I understand, owned by Elon Musk, this might not represent much of an improvement.
But what's changed anyway? What data do they have and what do they do with it? Phone number and messages obviously. I can't remember whether they "officially" have your email, but it seems sensible to assume they have access to everything that passes through your phone and could, if they wanted, trace your last bike ride more accurately than Strava and replay your last voice call. I suppose there's an argument that it's better for both Musk and Zuckerberg to have this data on the grounds that monopoly is more harmful than competition...