Ask HN: Vanilla JavaScript vs Web GUI Frameworks

After being a XAML/WPF C# developer for quite some time, I'd like to modernize my skill set and learn some web app development.

Ive seen React, Angular, Vue and all these well established GUI Frameworks over the years. Whenever I've tried learning React, I found the process very complex compared to WPF. I always get the feeling, if I'm using a layout engine, why don't I just use the basic constructs of that platform. This being plain JS, CSS, and Html.

Is it wrong or unproductive to start off my learning experience with the fundamentals? It sounds like an obvious yes, but I look around and see people going straight into React.

I don't want to go into something like React without knowing basic concepts. Also is there a good book on learning the fundamentals?