I had a thought recently that in the past 100 or so years we've had lots of ideograms in the West, and at a glance they all seem new. Things like "knife-and-fork" = restaurant and "stick figure wearing dress" = women's bathroom. And of course, such symbols are all over software.

(I'm aware emoji came as an evolution of emoticons from Japan, but for my question I think that's just one aspect of how ideograms have become more common.)

My question is: is this a real phenomenon, or am I falling for selection bias, etc.? Were there lots of ideograms in use in history that I'm just not aware of? Or are many of the ideograms we see today older than I would naively assume?

And then most interestingly, why? If ideograms have become much more common, can the reason for this be explained? Is it something to do with digital technology? Or laser printing? Or the pace of social / technological changes in the last 100 years?

Thanks. Hope that's an interesting and worthwhile question!