You are wrong about lightning. You can use a third party custodian, but it's possible to control the keys to your bitcoin locked up in lightning channels. At any point you can "withdraw" your bitcoin back to the main chain.

I think you are confusing the lightning network with liquid BTC [0], which is controlled by Blockstream.

[0] https://help.blockstream.com/hc/en-us/articles/900001408623-...