I think we should compare within the period I specified
That is, the period from the recent bottoms (both Litecoin's and Bitcoin's earlier this year) till now, and within this period specifically Litecoin is still a better alternative to Bitcoin if you primarily aim for speculation.
Litecoin is now underperforming since the bottom and is at its lowest ratio since 12-2017.
Whoever held on halvening hype got rekt.
that is partly because litecoin, like other altcoins, is taking effect from bitcoin and since during the LTC halving hype a lot of shit was going on in bitcoin market and price couldn't go up there was dumping all over the altcoin market including in LTC.
on top of that there was a lot of FUD and some reality coming out about how LTC development is dead, which it partly was since they just copy everything from bitcoin.
which is why i don't think we can call it "underperforming"!