Earlier quoted context omitted.
As far as I understand there is still some time before humanity becomes interplanetary in any meaningful way, maybe even many generations. And what is going on so far these days is mostly about not regressing.
Making rockets re-usable is a massive step forward and not about 'not regressing'.
That said: All the constraints on making it reusable and safe for humans are also a key factor why Space Shuttle was so expensive. With SpaceX's rockets not all parts need to resist the stress of reentry etc.