[blululu]

The photographic technique matters for image quality. You may have been looking at autochrome prints which used potato starch grains and typically had a long exposure time and a bit of a pointillist effect. For reference here is a collection of 110 year old autochromes of Paris:

https://www.thephoblographer.com/2013/01/31/behold-the-magni...

In contrast the 120 year old three channel photos of Sergei Prokudin-Gorsky from Tsarist Russia look like they were taken yesterday. https://www.loc.gov/collections/prokudin-gorskii/about-this-...