Litecoin and bitcoin cash has lots of similarity like low transaction fees, both are only used for payment and doesn't offer smart contract feature but litecoin is pretty old than bitcoin cash. I will rather trust LTC with my money than bitcoin cash which is basically backed by few millionaires who can easily dump all their free BCH on our buy orders.
Or you think I should invest in original Bitcoin? Is Bitcoin Core planning to solve scalability issue anytime soon?
Yeah there is plan for lightening network which will allow off chain transactions with almost zero fees.
You have a point on that. BCH, I think is still not mature in the market unlike LTC. So there's a chance that BCH will be gone in an instant once those rich holders decided to get rid of their bch. I believe btc is still worth investing as this is the frontrunner of all cryptocurrencies.