You don't need to imagine - just look up the SLS program and it's budget + timeframe
To give you an example of why it's a jobs program and not a rocket program. Congress forced NASA to build a multimillion dollar testing facility they never intended to use for the SLS nor for any other rocket NASA has.
Its not like NASA puts out a check and simply waits for the rocket to arrive. With the NASA process, they own the design, they are in meetings on specifications, they requests tests, ect. They micromanage and direct work down to the nuts and bolts, literally and figuratively.
By analogy, they are the head Chef in the kitchen. With SpaceX, they are the customer at the restaurant.
This doesn't compare at all with the SLS, which is just recycling old tech, and even going backwards from the Shuttle in that it gives up on reusability entirely instead of trying to learn and improve from the Shuttle's mistakes.
Calling Falcon Heavy and SLS equivalently government-led is laughable. The amount of by-design government red tape and congressional district handouts is astounding.
Congress cared that it met payload requirements and mission requirements. That these institutions were unable to deliver within reasonable time and budget limits is a result of their own dysfunction.
Since rocket production is extremely capital-intensive, the market is very thin. The number of players capable of even giving it a go is low. And thus, it has all the hallmarks of a typical market failure.
Private companies the entire time could've realized the potential profits and competently worked to achieve them, even outside of begging for government contracts. That they didn't do this for many decades is their own fault.
This is just not correct if you mean that they only cared about payload and mission requirements. Congress mandated that certain technologies were to be used from non-competitive, single-source suppliers in order to prop up industry in particular congressional districts. Cost overruns are practically by-design because as long as it doesn’t raise too many eyebrows it’s just more money to their local industry and constituents.
Now that there is a critical mass of billionaire nerds and venture capitalists who want to build rocket companies, there is now competition in this sector. It is a case of monopoly vs competition. That is the real answer.
This is completely false. SLS was established by Congress with various mandates on the technology and process to design and build it.
Falcon Heavy was not.
Many of the issues with SLS can be traced to Congress's requirements that they put on the project, like forcing it to reuse 50-year-old STS technology.
SpaceX over the last two decades has been a superb illustration of the value of private enterprise.
SLS follows the old model of NASA contracting where NASA sets all the design requirements and the contractor follows them (ie the choice of solid boosters, the use of Shuttle technology etc was all set by NASA and the final vehicle is owned and operated by NASA). The contractor is effectively given a blueprint and asked to build it, with all construction costs covered.
This is in strong contrast to F9 and FH which follow the new model where the government only sets the rough requirements (payload capacity, target orbits, vibration tolerances etc) but doesn't care about the specific details (beyond making sure that they make technical sense). Payments are made for reaching specific milestones, how that relates to internal costs is entirely on the contractor and the final vehicle is still owned and operated by the contractor, with NASA acting as just another client. It's a much more hands off approach compared to SLS.