Is there functionality whatsapp provides (even if it’s really unrelated to software features, just by happenstance due to its widespread usage) that signal doesn’t currently provide for? If so, it’s a losing battle. No one would go backwards in functionality unless the ads got egregious.
What you consider important may not be what others consider important. Seems like you know of other features that others find important you’re just not wanting to mention those because it undermines your point.
