Litecoin is losing its status as a silver of crypto. People started to abandon it as it gives no value other than capital gain. You get nothing when holding LTC, i think that's the reason people are not massively using it as investment.

As for Monero, since the regulation is getting stricted to the crypto. It's impacted all of centralized exchange sites, which has become central of liquidity. The order by regulators to ban anon coin from cex is giving massive impact to the monero. It's hard to sell or buy it since it can be done only through p2p.

In conclusion, Both Litecoin and Monero are not worth investing.