1. It's easy to underestimate what is possible when you limit thinking to a short timescale. I think of the cathedrals, temples, mosques, etc. that have been built all over the world, where the people who started the work knew they wouldn't live to see it finished, but that didn't dissuade them.
Or conversely, it's easy to overestimate the difficulty of something if you are too constrained by thinking in terms of finishing it relatively quickly.
2. Building things does make it easier to build things - and conversely, not building things makes it harder. There is a lot of architectural stuff in our world today, particularly fine masonry and woodwork, that is still common because so much of it was made up through the 1930's or so, but which is actually quite difficult to produce today because most of the skilled labor and the industry that supported it is gone.
This also reminded me of an article about scientific glasswork, which is similarly dying out[1], and of course more familiar to the HN crowd we know about old technology that was once common and now is difficult to replicate or maintain.
Lots to think about.
1: https://www.latimes.com/local/education/la-me-caltech-glassb...