To tackle the scalability problem of Bitcoin the lightning network was introduced, which (if I understand correctly) adds an additional layer to the blockchain, allowing users to create a payment channel between any two parties on those layers. Transactions on this channel will be fast and cost little or nothing.
Now my question is: Is it possible that Lightning Network payments may someday replace all Bitcoin transactions, rendering the block chain obsolete?
In order to join the lightning network, you will generally need to create and publish a bitcoin transaction.
Likewise, to reposition your funds in the lightning network, or to move bitcoin out of the lightning network, you will need to create and publish a bitcoin transaction.
So it doesn't really make sense to say that the lightning network will 'make the bitcoin blockchain obsolete'. Even if every single payment happened on the lightning network, the bitcoin blockchain is still required, as it's liveness is what underpins the security of funds on the lightning network. If the bitcoin blockchain disappears or stops functioning, then lightning too will cease to work.
