The forerunner of Crypto was able to develop as it is now because of these two coins, these two coins will dominate for the following years.
So people are more confident that their big money is invested in these two coins. because btc is a pioneer of crypto and eth is a pioneer of smart contracts.
who says that there are big money invested by more ? have you also invested in Bitcoin and ethereum? not because there are big amount in capitalization meaning so much people putting inside m because there might be whales that handles most of those amount.
but still I am for Bitcoin even if we are talking for longer time here.