Presumably, we'd launch more of them, *if* we wanted to go back to the Moon.
Hasn't been the case in practice. Saturn V, Shuttle, Constellation, and now SLS have all sucked oxygen out of the room for actual exploration and development of the Moon and elsewhere. They've never achieved the launch frequency, reliability, or cost savings to justify their use. And aside from the Saturn V era, we've never had the need for the capabilities (particularly, the large payload and fairing size) these rockets bring,
For example, this blog post discusses an alternate past where the Shuttle wasn't built and NASA instead continued on with the Saturn 1B and a small reusable manned vehicle (say 3 people plus cargo, a bit better than the Apollo capsule in payload).
They could have still flown everything that the Shuttle flew for 30 years and have a demonstration of a reusable vehicle at a small fraction of the cost of the Shuttle.
Another alternate past. Consider that we knew after the Challenger accident that the Space Shuttle would never achieve a launch frequency that would be economical. Discontinue the Shuttle in 1990. From that point on, there was only one thing that ever required the features of the Shuttle, the Hubble Telescope repair missions which simply weren't valuable. Instead, hustle the development of the EELV (Evolved Expendable Launch Vehicle) program (which built the Delta IV and AtlasV rockets) so that it was developed a decade earlier in the early 1990s instead of the early 2000s.
Then everything that was done with the Shuttle could then be done with EELVs, such as building the ISS or launching space telescope replacements for Hubble, with the use of EELVs, saving tens of billions of dollars over the 20 year period through 2010 and boosting commercial space flight in the process. And when Falcon 9 was developed, it would easily slide into this NASA strategy where everything is launched on rockets of that size.