They are two different propositions. Ethereum has more long term potential. When I say long term I'm talking 5 to 10 years. Dont worry bitcoin is not going to disappear any time soon.
yes bitcoin even has more potential, because the price of bitcoin already cross 2000 USD level and still going to increase. people are are still very confident about bitcoin they are even not going to sell their bitcoin and going to keep them for next high price.