Who built Sydney? (and other cities) - Is our history fake? 5 mins

If we really did build these cities with wall to wall brick and concrete buildings, with such precision and beauty, why did we stop? Why do we now take 6 months to build flimsy single brick homes with, soft wood frames and gyprock walls?
The builders back then seemed to have such excess time, resources and labour. Its like there was a blank cheque. So much uneccesary excess of beauty and ornate features in the buildings.
Why could we build all of this in the 19th Century without it causing financial hardship, when the Sydney Harbour Bridge took 8 years to build (completed 1932) and 56 years to pay off the loan, nearly sending the city broke?
Why are there no signs of construction in the many thousands of photos?
Why are there no photos of horse and carts transporting brick and sandstone?
Why do a lot of buildings show significant weathering by the late 1800s?
How was the sewerage system, pipes and tunnels installed underneath the streets?
Why were there so many diverse occupations depicted in the city's business signage and no signs or mention of builders, tradesman or construction companies or suppliers?
- Thanks to:
Jon Levi - https://www.youtube.com/channel/UC5vXBfxN7rxKeJHJxS8dNDw
Kelly - Tartaria Australia - https://www.youtube.com/c/KellyJonesTartariaAustralia
Campbell - Auto didactic - https://www.youtube.com/channel/UCSsz5hijS79cioRCJcZpW2A,
Tartarian Truthers - https://www.youtube.com/c/TartarianTruthers
- check out their youtube channels