Unfortunately I believe the only way to ensure something like this would be to run your own lightning node with enough routing that channel peers want to keep a channel with you.
IMO long term the only thing I'd worry about is on-chain and their UTXO management. Todays scaling solutions probably won't be tomorrow's. I'm confident that there will always be a way to transact cheaply, but hard to say what that looks like 10yrs from now. Only thing I'd be willing to bet is that there will be a path from on-chain to that scaling solution