I asked AI on this: You are correct. If you don't have your own Lightning node with an open channel with a very large digit, you will need to rely on custodial wallets to send or receive large amounts of Bitcoin. This is not very practical because it requires you to trust a third party with your funds.

There are a few ways to avoid this. One way is to run your own Lightning node. This will allow you to open channels with other nodes, including those with large digits. However, running a Lightning node requires some technical knowledge and resources.

Another way to avoid custodial wallets is to use a decentralized exchange (DEX). DEXs allow you to trade Bitcoin directly with other users, without the need for a third party. However, DEXs are still in their early stages of development, and they may not offer the same liquidity as centralized exchanges.

Finally, you can wait for the Lightning Network to mature. As the network grows, there will be more nodes with large digits, and it will be easier to send and receive large amounts of Bitcoin without relying on custodial wallets.