Bitcoin's L1 architecture makes widespread self-custody on the L1 technically infeasible, regardless of setup (single-sig or multi-sig). Self-custodial Lightning wallets have proven inadequate due to their complexity and channel liquidity requirements. Sidechains like Liquid are not a viable solution either, as long as BTC can only be moved to L-BTC with one's own node but not vice versa. A truly decentralized L2 is needed, where billions of users can securely keep small amounts of BTC in multi-sig wallets and easily move it to the main chain when the UTXO exceeds a million sats.