Second-tier networks such as Lightning Network (which relies on SegWit) cannot be considered as a block scaling solution. LN transactions are NOT equal to Bitcoin’s peer-to-peer on-chain transactions and most Bitcoin use scenarios are not applicable with Lightning Network. LN will also lead to big payment “centers”, and this is against Bitcoin’s initial design as a peer-to-peer payment system. It can be a good method though for frequent and small Bitcoin transactions in certain cases. But we cannot rely on it as a cure for Bitcoin scaling.