ETH and Waves will be far ahead LTC. ETH will strugle to keep price higher than Waves.
Waves will still in the bottom rather than the litecoin's price, The ethereum should be a winner from dash and litecoin in the future, it was offering many advantage by using the blockchain smartcontract to the real usability. The price of ethereum will be very high after the metropolis. Why do you compare them with each other? They're totally different ones. Waves may be $15, Ethereum may be $600, Litecoin may be $75 for 2021. Not more, not less. Never expect 100x kind of pumps from this altcoins.
Ethereum's hard fork will be important for its future.
If your suppositions are rights, it means that the global crypto world will only double within 4 years. According to me, if it keeps going up, it will be way faster than that.
--in the future of the internet itself. Litecoin will do what litecoin has always done, be technically superior to bitcoin but live in its shadow for all eternity, should have some nice gains though. I don't have an educated opinion on WAVES yet, ask me in November when I do my next round of investing, it is on my personal research list. 
