Does an @Aspect have to be a @Component?

Question

I made a tiny app to check a few things. Here's the code (assume all the files are in the same package)

@Configuration
@ComponentScan
@EnableAspectJAutoProxy
public class Config {
}

@Component
public class SomeBean {
    public SomeBean() {
        System.out.println("Creating SomeBean...");
    }

    public String someAspectedMethod() {
        return "some string";
    }
}

@Aspect
@Component // note this
public class SomeAspect {

    public SomeAspect() {
        System.out.println("Creating SomeAspect...");
    }

    @Around("execution(String SomeBean.someAspectedMethod())")
    public Object methodAdvice(ProceedingJoinPoint joinPoint) {
        System.out.println("Running methodAdvice()..."); // never gets printed
        Object object;
        try {
            object = joinPoint.proceed();
        } catch (Throwable e) {
            throw new RuntimeException(e);
        }
        return object;
    }
}

public class App {
    public static void main(String[] args) {
        var context = new AnnotationConfigApplicationContext(Config.class);
        SomeBean someBean = context.getBean(SomeBean.class);
        String returnedVal = someBean.someAspectedMethod();
        System.out.println(returnedVal);
        System.out.println(returnedVal.getClass());
    }
}

Console output:

Creating SomeAspect...
Creating SomeBean...
Running methodAspect()...
some string
class java.lang.String

I noticed that once I remove the @Component annotation, the aspect is no longer applied

@Aspect
// @Component
public class SomeAspect {

Console output:

Creating SomeBean...
some string
class java.lang.String

Which begs the question: why isn't @Aspect a @Component (stereotype annotation) just like @Service, @Repository and a few others? And if @Component is not necessary for aspect classes, then why does the lack of it effectively disables my aspect?

This doesn't answer my question

Answer 1

@Aspect is part of the AspectJ library, which is a stand-alone library that shipped with Spring and therefore, Spring can't change the @Aspect annotation source code to add the meta @Component (spring can't make @Aspect a stereotype in another word)

@Aspect is part of aspectj annotations: org.aspectj.lang.annotation.Aspect

for

if @Component is not necessary for aspect classes

@Component is there just to register the Aspect in the application context via component scan (@ComponentScan that you add to Config class let Spring search for stereotype annotations and register them in the application context)