I asked if people chose iPhone for the blue bubbles elsewhere a couple days ago, and while there was some good discourse on that post, the blue bubbles definitely also came up as a reason.
In my experience, when people find out my texts are green, they oftentimes would rather switch to a different platform altogether like Instagram or just not text at all.
Is this actually a deal-breaker in friendships out there?
Signal is the best in regards to privacy.
Signal uses the same E2E encryption as WhatsApp and is also not Open-Source. One could argue that not being owned by Meta makes it inherently more private, to which I would somewhat agree.
The most private Messaging-App would be some kind of federated Chat, like Jabber or Matrix, that you or a collection of family/friends can self-host.
Unfortunately, nobody uses those ¯\(ツ)/¯