I mean, it's all abstractions for the most part, the core is still HTML/CSS/JS just written in a more productionized/sustainable way both to make development as well as long term maintainability easier. Hypothetically speaking, since I'm not using a Node runtime (at least until I get to completely sever the front/backend) you could write the whole thing in a vanilla stack, that's what it gets compiled to and you can even see it's output! (Note that link will likely not work when I make a new release, you'll notice there is a hash on the file name which will change on a new release to ensure you don't use the old cached version after a new version comes out). Front-end code is interesting that way since all code compiles to vanilla Javascript that your browser can understand (with the still relatively rare exception of Web Assembly, though it has not caught on for many reasons).
Regardless, as a new dev you're doing the right thing, learning the basics. You could always add layers of abstractions later to make yourself more efficient, but understanding how things work 'under the hood' is one of the most valuable skill sets and IMO what separates the great from the wanna-be.