[crikli]

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.

[iuygtfrgth]

Not quite - we use very large expensive rockets to launch very large expensive payloads. The rockets are large and expensive because the payloads are large and expensive - which they need to be because launches are large and 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.