Around 20-30 years ago, people took a little more care in composing a photo, even the amateurs. Hard drive space was still kind of pricey. Smart phones weren't ubiquitous yet. It took some level of real investment to create the kind of photos you miss. Lego landscapes are hard. They're tiny and big at the same time. Focus, depth of field, and lack of a background all work against you in ways a little diorama doesn't. Combine that with more people that haven't actually studied the craft of photography, taking more photos than ever and you get flooded with snapshots. Those lazy snapshots still happened 20-30 years ago to be sure, but nobody's remembering them because they were forgettable then and forgotten now, kind of a survivorship bias. The same reason people argue that the music they listened to in grade school always was and forever will be the best music.