You are experiencing what I call "The Bisquick Problem". Bisquick is basically flour with some other stuff, like salt, premixed into it, and sold in a box in the USA. So instead of just buying flour and salt, you buy them together, which makes some things easier (like making pancakes), but it complicates literally everything else. You can't use it as flour, or as salt.

With software, the problem is even greater. You can use react, for example, but you will probably start with create-react-app, which adds a lot of things. Or you could start with Next.js, which adds a lot of things. You could use Java, but you will probably start with Spring Boot, or Dropwizard, which adds a LOT of things. Plus all of these starting points imply the use of new languages, configurations, and programs, in particular, builds.

In my view, all of these "Bisquicks" represent experiments-in-progress, with the ultimate goal of the systematic characterization of "software application", in general. In other words, they are systems of alchemy, pushing toward being a system of chemistry, which we don't have yet. So it is bound to be a confusing time, just as it was surely confusing to play with chemicals before Lavoisier systematized the practice.