Bitcoin seems to be the past and Ethereum the future.
The question is : when BTC will worth almost zero? Next year? In 2 years?

Both cryptocurrency are a good choice for anyone who choose to invest in any. As for me I will always prefer Bitcoin as the number one ,but ethereum will always be my second best crypto. Sometimes it fails,but after that it never fails to recover.
Just like what happened recently ,a lot of people were already giving up hope on whether to continue with ETH or not, and just in a day it was able to recover 80% and went back to the second position.