At least in my circles Roam has been absolutely impossible to miss even if living under a rock. Before Roam, people around me used either Evernote or OneNote or some kind of text files in directories scheme, all of which apparently sucks for other people just as much as they do for me.
Most are now on Roam or Obsidian, and I hear that at least in some in scientific circles Roam has made an even bigger splash. I've tried Roam and Obsidian and a few copycats and stuck with Roam, and it's lightyears ahead of what I had before, but there seems to be no good way to interface with the graph using code and that's limiting things severely for me. Still looking for something better, but IMO it's absolutely fair to say that Roam has had a huge impact.