I have a theory that while human tech is mostly average, MCU weapons tech is massively above board, and MCU spaceship tech is way below average for species on the same level. It helps keep humans as a relative threat to alien invaders, while stopping the story from changing into something else entirely.
It also holds true in real life. Could you imagine with rocket and space exploration tech followed the rate of progress of the computer, following Moore's law? We'd have colonised the solar system by now.