And who will pay the miners if all txn fee subsidy is off chain on a third party network?

Bitcoiners so far up their ass they can't even read the abstract of the Bitcoin whitepaper, or they do and either don't understand it or completely ignore it because some influencer told them that it's the way forward.

There's a reason why Satoshi hated developers and wanted a protocol that wouldn't be fucked by them, yet here we are.

Ecash and lightning together could potentially do it within a decade. But then we will still have the same problems because you can't verify eCach. Scaling to everyone means most people on a mint right now.