The Opera of today is not the same as the one from back in the days! The original company sold all their code and rights to a chinese consortium in 2016. Since then it’s basically a variant of chromium, with some propriatary features and tracking added. I don’t know the new owners, so I don’t trust them with my browsing data!
Signal if possible, WhatsApp if not. I’m also trying out Session, but it’s still very much work-in-progress.