Keep in mind that Ethereum starts 3 years ago while Bitcoin starts 9 years ago. Also consider the fact that Ethereum can handle more transaction per second than bitcoin.
You might also want to consider the fact that bitcoin is handling more volumes of transaction than ETH, and thus is the reason why ETH can now handle more transaction per second than bitcoin but I doubt if it will be fast or slow if it begins to have at least 70% of the current transaction volume of bitcoin. Nevertheless, I think both platform will be at par with each other in the future in terms of security.