TL;DR version of this TL;DR version:
We use rockets to get to space because getting as good at other methods is too expensive.
We use rockets to get to space because getting as good at other methods is too expensive.
Imagine if Nasa had been in charge of developing aviation in the US - you certainly wouldn't have Cessnas and 737s.
There is a brilliant parody about Nasa being in charge of the old wagon trains going into the weat and their plans to make one giant wagon that would be able to make the journey and return safely.