These are crazy high quality it makes it reallyy questionable. I just looked up photos from 1900 on getty images and there's a graininess to them and a distinct quality to them. But I'm no photograph expert.
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:
some of these photos look like they were taken with a field camera on plates, a technique that can achieve higher resolution than modern consumer digital cameras. you may be looking at some smaller format for your examples.
most people have never seen a real photography exhibition and don't realize the extreme detail and depth that can be achieved with analog photography, and has been possible for over a hundred years. consumer cameras are oriented to convenience, but film is so much more powerful than the toy cameras you might remember from when you were a kid.
In my family we had a book made at an unusual, large, awkward size. The book was essentially a photo album and the pages essentially contact prints from large glass plates. The subject was the construction of the Central Pacific and Union Pacific railroads to form the first transcontinental railroad in the US. In one picture, a very large wooden trestle bridge had just been completed, and the builders were all over it, if you could find them. The exposure time was long enough to turn the rapids of the river below feathery.
The photographer kept the camera and his supplies in a horse-drawn wagon, which was also the darkroom.
