This is a retarded take with 0 understanding of any of the underlying.
Lightning is just recycling on-chain transactions, if you can make a chain tx you're able to be onboarded.
No solution solves for 8bn UTXOs, fortunately that's not a realistic requirement. Community nodes are the reality.
Mobile node devs are just taking the lazy route to not look like custodians, even though most can still rug users with an update. Phones are thin clients, period.
Lightning Pub fixes sharing of remote nodes.