It is impossible and will not happen, I myself do not find a factor to strengthen the statement that Cardano is able to overthrow ETH, maybe the cost problem at ETH has not been resolved, but some time ago the cost of ETH was cheap. ETH has come up with an innovative design to solve this problem and let's see how powerful ETH is.
There is no need to hesitate for ETH because from time to time ETH is always strong, and for today I have checked the transaction fees on the ETH platform which are quite cheap at 50Gwei, so it won't be easy for any Altcoin to subvert ETH under any circumstances.