I'm going to nit this for several reasons:

1. Walking on the moon implied a return trip which requires an extra ~3km/s.

2. Under the rocket equation the fuel requirements for more delta v grows superlinearly, which then awkwardly makes your rocket bigger, which requires more fuel...

3. 22 years prior a metal can went to space. The scale of a manned moon mission in comparison is absolutely nuts, even basic things like having rocket motors that can be relit is a large technical challenge.

Addendum to point 3. It's not just a metal can, it's a metal can with some people in it. You have to keep them alive and useful for roughly a week, not just fling them at the moon.

A full up Saturn V with LEM and the works looks a lot more complex and capable than a 60% improvement on a V2.

But the additional complexity is mostly designing a suite of vehicles, not general rocketry advances.

Incorrect. Orbital mechanics were not a part of the V2 era programs because they were sub-orbital with relatively simple parabolic trajectories. Getting a capsule back from LEO was not something that had been worked out mathematically until later.

V2 does NOT go into orbit.

Yet another reason why the comment I'm replying to was incorrect, thanks.

No, it’s actually the opposite. Re read. If you compare an actually LEO capable vehicle and a moon lander of the same payload, you’ll see that the difference is not that big.

Saturn had a massive payload, hence the gap in difficulty.

But my point anyway was that Saturn V is not 1000x larger than a soyouz, despite the moon being 1000x further away. Distance is not what counts in space.

The delta-v from Earth Surface to the bottom of the ocean is 0, so by your logic, going there is trivial.

It’s a measure of the energy needed to move from one orbit to another.