If you did a Spring tutorial, I can see that this might be the takeaway. For me, I was thrown at a large project with a couple of large Spring codebases, I concluded that it's about structuring your code around an object graph with independent, testable, loosely coupled components.
I use both Spring and Java professionally. For a pretty long time now. I was being somewhat sarcastic.
I mostly use Spring because it's pretty widespread and I figure - why fight the current. But I still think the benefit is minor for most projects. And the existence of Spring Boot makes me chuckle a bit.
I get you. I think it encourages a certain application structure that is at least recognizable across projects. There's a pretty big benefit to that, even if at the detail level it's just a way to avoid new.