Why haven't browsernative, zeroidentity messaging apps replaced traditional ones?

why does signal still need my phone number? honestly wondering why disposable browser chat rooms arent the default for privacy yet. even with signal you need a sim card, telegram keeps logs, and everything is tied to google or apple stores anyway so you are never actually anonymous. browser crypto is solid enough now to do real end to end encryption without accounts, phone numbers or installs, just nuke everything when the tab closes. is it just that nobody can monetize an app without user data, or is there some technical blocker im missing?