In Formula 1 is the pinnacle of open-wheel, single-seater car racing and arguably the highest level of any motorsport globally. Also... There's more..., reliability is everything.
A team can cover the smallest of details to gain thousands of a second, but if there is a reliability problem all the hard work of the hundreds (even thousands) of people supporting the car is all for nothing.
To finish first, first you have to finish – Sir Stirling Moss