there is no way that cardano (ADA) can overthrow ethereum because the market cap is always superior to ethereum than cardano. so it is very unlikely that cardano can be better than ethereum because we all know that ethereum is the best altcoin of all time. but for the price of cardano to reach $12 it takes a long time and this can happen in the crypto market.
There's should be no comparison, even cardano is moving forward but ETH already on the top to catch up there are many things that this coin have to
consider, support from community is what ETH already established, cardano may formed it's own but we also need to see other competitions in which
ETH already passed. Maybe in price if you are looking for good investment and you can't ride with ETH, cardano is one of those many that you can
use now and wait to hit your target.