[throwaway7783]

It is the programmer's job to learn what is going on. Java itself doesn't hide anything from you. You are free to write a servlet from scratch, or use a framework like Spring to hide everything. Your (company's) choice really.

People end up choosing something that has batteries included so they can focus on solving business problems. A programmer who will superficially understand SpringBoot without understanding how it works. Really, there is no magic there - its a few core concepts - annotations, bytecode enhancement and dynamic proxies. Maybe Im missing one or two. Everything else is built on top of this.

This is regardless of language/ecosystem. If I do not understand the fundamental concepts, I will never be successful in that ecosystem.

[zeroc8]

The layer in Go is much thinner, if I want to learn about a new concept or technology. Of course there is no magic, if you are willing to put the time in. The question is how much time is required.

[gf000]

The layer is thinner because you can't create abstractions as well in that language.

But that's like saying that a bicycle is better than a car, because the first is simpler to understand. (At the same time, nothing prevents you from assembling a bicycle in Java if that's indeed what you need. But for general long distance travel you are better off starting with a car frame, aren't you?)