For non-custodial LN wallets, liquidity ads and the LSP spec are liquidity management solutions (realized in code such as https://github.com/lightningdevkit/lightning-liquidity and by services such as Voltage and Olympus). Ark and statechain-based solutions take different approaches. Yet other solutions such as Fedimint and Cashu, or Cash App and Coinbase, because they're custodial/pooled funds, avoid those challenges altogether.