Why are all the Big World Buildings the same in almost all countries

The big buildings, all of them dating from around 1800, so they say, they have the same architecture, in a world when resources and man power was very limited. It looks as if the whole world belonged to a different humanity before 1800 who built all this and then something huge happened and only the big buildings remained. If you like my channel: Instagram: Patreon: (currently not posting new content) PayPal: Shop: Facebook: Twitter: