If I have to see one more "look how they made this photo black and white to make you think it was older!!" appended to a post with photos from the 1960s/1980s/whatever decade of the later 20th century, I will perish and dissolve into dust.

Please be aware that not very long ago (before 2000 or so) the default standard for journalistic photos was black and white, because that was what newspapers and magazines could reproduce in a cost-effective manner. Only Sunday papers or glossy high end magazines routinely had any colour photos at all. The same goes for things like textbooks or academic works - if they had to reproduce a lot of photos, black and white was much cheaper and easier, so that was standard.

Nobody is "making" photos from 30/40/50 years ago black and white - for the most part, they were shot in black and white because that was the standard then. That was what most 'serious photography' looked like. If you were developing and printing your own photos (as many photographers did), black and white processing was easier to do - hell, I learned it in high school in the 1990s.

Colour photos, although they existed, were harder to reproduce in mass media - they required colour correction, so things didn't look weird depending on the lighting or the printing, and it was more expensive, time-consuming, and needed different equipment. That's why Sunday papers were more expensive, and only put out once a week. As well, the colours didn't always hold up well over time - if you've ever seen colour photos from the 1970s where everything looks oddly yellow, that's the colour processing deteriorating over time. Black and white film and prints were more stable long-term, cheaper, and more easily distributed, so they were typically used for journalism, art, and other situations where you wanted your photos to be taken seriously, last for a long time, and potentially be widely distributed and reproduced over and over consistently.

It's not some big conspiracy to stop people from realizing that things happened more recently than they imagined - it's just how a lot of photography worked before 2000.