The transistor, integrated circuit, surface mounted component robotic pick and place machine, laser and fiber optics. In the software world, countless of ideas. Open source too. Whole generations of software developers. All those were needed for the information age, not just throwing money to scale up Sage or Sabre or VAX or anything.
A more physical example is the rail network in the US. It's often asked "why don't we have high speed rail in the US?" Being a nation of autophiles obviously doesn't help but it's not as simple as putting higher speed trains on existing track. It's not even as simple as replacing the existing track with track that can take a higher speed train.
The rail network we had is an artifact of the performance constraints of 19th century trains for the most part. Top speed is the most visible constraint. But the grading, turning angles, etc are all a function of much lower constraint on top speed.
We'd probably be better off if we had no national rail network at all, which is pretty much the situation China was in. Admittedly there are other factors in China's rapid HSR deployments (eg streamlining planning and acquisition of land).
But I digress. Timing is hugely important in scaling.
As for HSR, do we really need it? It might make sense in the northeast corridor but it's hard to make a business case elsewhere. The California HSR project has turned into the usual government megaproject boondoggle with long delays and cost overruns. Even if it actually gets built I'll probably never ride on it.
One should look at the operational capacity, not the theoretical capacity. Who cares if you have an airplane that can theoretically do Mach 3 if it's being repaired in the hangar and you need it now? In airplane lingo a plane like that is called a "Hangar Queen"
Falcon 9 is a huge step in the operational direction. But more is needed. Can one do two flights in 24 hours? Can one save the second stage too? Just the fairing? Or can one make the second stage cheaper? Or salvage it in orbit?
There are other ways to reduce cost, such as cheaper rockets, more efficient fuels, etc. Whatever SpaceX does isn't the only possibility or a necessity.
The "cost" of Shuttle launches was calculated as NASA's entire manned spaceflight budget divided by the number of scheduled launches. They paid salaried staff all year no matter how many launches happened. That cost was trending downward as the number of launches increased prior to the Challenger disaster. After return to flight after Challenger NASA cut the launch schedule but had to pay the same infrastructure costs so Shuttle flights got more "expensive".
I read a recebt biography about Von Braun and IIRC the entire project was designed to scale up, and all of that was hastily thrown away for the ineffective shuttle program.