How to sell Signal to co workers?

I work for (semi)government in the Netherlands. We use WhatsApp to communicatie about times, meetings and relevant newsarticles. We try avoid using names or any details of our work.

But i want us to switch to Signal for obvious reasons. But how do i pitch this? I want to avoid politics, because an easy excuse not to switch would be, as government workers we are neutral in politics. So i think ill aim for WhatsApp using meta data and US tech might be less reliable. Any thoughts on this one?