Multi-launch was considered for the Apollo program, but was ruled out because it had higher technical risk than just scaling up the rocket and making the payload extra light. If we didn't have the hard 1969 deadline we would likely have gone with the multi-launch option back then.

It's an interesting alternate reality to imagine: we might have had a more interesting moon program that had the ability to naturally scale to larger and larger missions, instead of repeating basically the same thing until the public gets bored and cancels it.