This comment is at the same depth of analysis of saying that the only reason for python being successful is that universities started teaching it and then people no longer could do C++
I personally feel they are for the simplest reason that Web Development exploded to the point the new blood and cultural migrants outnumbers and outproduces the old. Those lessons were taught, and kept, the mundane act of googling anything suffixed with "... in React" being the kiss of death that settled it.