If we had funded that as much as we're currently funding AI I think it would have been a plausible goal. Keep in mind we cut more than half of NASA's budget after we first landed.
>It was only six years to go from the first multi-person spacecraft and first spacewalk to the first space station.
Yeah that's my entire point, technological process doesn't have a constant rate of acceleration. Some advances are quickly made one after another and others lag and take a very long time.
How long do you think it would have taken to get a permanent moon presence if we kept up Apollo level funding indefinitely with that as the main goal? And since I only said "plausible", let's go with 80th-90th percentile best case scenario.
Even if technological progress stopped we could have launched enough parts to assemble a colony structure.
This is splitting hairs, but I was envisaging something more like the ISS but on the moon. A far cry from the 50s/60s dream of a grill and white picket fence on the moon.