As I understand it BTC doesn't have the bandwidth required to use it as money (TPS). Therefore, something else is needed to make this possible?
Either by upgrading BTC or building something "like" lightning network?
Is it a proper critique of lightning network that it's not simple enough for most people to use it as money in a non-custodial way?
Bitcoin is money already. Unfortunately, however, it may not be the everyday money that people imagine. It could be a money for final settlement though. If it can't be used to buy a cup of coffee, a sachet of toothpaste, a packet of salt, or a piece of banana at the convenience store next door, then it can only be a limited form of money. It is money nonetheless.
We've been advised to keep our coins in cold wallets but it is also widely acceptable to keep small amounts in hot custodial wallets for small transactions every once in a while. This might be the same with the use of on-chain and off-chain networks in payments.
The Lightning Network I'm afraid isn't only
not simple for the common folks, it might be flawed also.