ETH and WAVES could rise up someday, the reason why some alt coins are correlated with the dump and rise of bitcoin is because of the investors keep investing on both coins with the same amount of money, and we all did that at least once. Anyway, I don't see tether becoming a big things, they already disappointed people on their hacking incident ( though i don't believed that they are hacked or who knows).
Bitcoin is the benchmark for all altcoins and no alternative coin can take its place or even come closer to it in any aspect. I do like Ethereum and waves. Not only these two but I think Monero, Litecoin, neo, Omisego and ripple are also good choices.
However, none of them can match bitcoin. Nobody knows the exact future but if we look at the past performance of bitcoin and its present static, we can make a prediction about its future. Most probably, it won’t crash.