As far as scaling, Segwit, and Litecoin... it is more of a precautionary implementation. It is better for the capacity to be there when you need it rather than waiting to implement it until after you need it.
As far as Segwit, LN, and Litecoin... it is not only about scaling. Ignoring the scaling benefits, there are a lot of other benefits:
LN:Instant transactions
Cross-chain atomic swaps
Lower transaction fees
Reduced blockchain bloat and load
Anonymous transactions by use of onion-style routing
Sub-satoshi payments
Segwit:Fixes malleability issues
Lighter full nodes are possible (you can opt not to download or store signatures, and leave it to the witnesses)
Lighter light nodes use less bandwidth and disk space (don't need to verify signatures)
Miners can maximize fee income and users can more reliably calculate the needed fees
Makes advanced scripting (smart contract) easier
Reduced blockchain bloat and load
More info on Segwit benefits here:
https://bitcoincore.org/en/2016/01/26/segwit-benefits/More info on LN benefits here:
https://en.bitcoin.it/wiki/Lightning_Network