From my experience hiring and mentoring, I reckon a lot has to do with how (overly) complex stacks for web application development have gotten. Thus people often having to learn in a very top down way, learning the very high level tools first and have little understanding of what lies beneath. There is also at least the perception that there are a ton of those high level things you need to understand for being a "fullstack" dev and it is also this top layer that actually moves fast, whereas the fundamentals move in a much more glacial manner. People chasing changes and additions instead of deepening their knowledge.
If I compare that to my own experience learning web dev in the early 2000s on my own. Make a html file with some css and ftp it up to a server. First version done. Add some JS, some PHP, then a database. Eventually move from vanilla code to different frameworks and languages, move from a Linux box to some cloud services, slowly start working with more complex systems and different paradigms. The whole process was very iterative and I feel I have gotten a lot of transferable knowledge on the way.
Of course this is perfectly possible to do these days as well, but it is not what I see happening or being widely encouraged in communities or fostered within companies. It seems more about run this and that generator script, click this button to spin up the managed services to run it on. See, it is so easy, so no problem. Creating hundreds of dependencies and layers of abstraction with practically no idea what they do. I had people wanting to learn programming from zero asking me to help with issues with their docker setup before having written a nested for loop.
I'm definitely not against those "modern" tools, they can be an awesome productivity boost if used well in the right context, but I can't help but often feel reminded of the good old Jurassic Park quote when it comes to tech stack decision making: "Your scientists were so preoccupied with whether they could, they didn't stop to think if they should"