Transferability is a basic primitive of crypto but not the only feature. Others like decentralized escrow and multi-signatory wallets achieve new functionality that is non trivial in traditional banking system.
Uhh, multi-signatory bank accounts are about as old as banking.
In comparison you and several friends can set up a m-of-n account in a couple of transactions, closer to the flow and ease of setting up a new WhatsApp group.
The value fluctuates but this is where users would typically send USDC or DAI which is pegged to the dollar.
My crypto transfers also arrive in seconds and there is no US company extracting rent, blocking my funds, asking for third party data, or dictating how a payment protocol should operate.