Lightning Network is not centralized, anyone can run a node with their own wallet. Not everyone will want to, since there are management and safety tasks involved, but that’s up to each one.

Funds are stored in your own wallet… but again, you can use some bank’s wallet if you want to, up to each one.

Transactions are almost instantaneous, no need to wait for the channels to settle. You only need to wait when moving Bitcoin between non-LN and LN wallets or, if running your own node, when a channel closes.

You can find a list of physical stores accepting LN… mostly in El Salvador, but still.

en.m.wikipedia.org/wiki/Lightning_Network