I think bad rep is partly because Spring (and Spring Boot), Quarkus, etc. don’t need any Glassfish or Websphere and can be deployed barebones or run in Docker containers without hassles of having to manage “application servers”.
You could also say btw that GlassFish doesn't need any WebSphere or JBoss. Or you could say that WebSphere doesn't need a JBoss or GlassFish.
Also, WebSphere is legacy within IBM. Their new and much much better server for some time is called Open Liberty. It uses some components from WebSphere, but in a highly modularised way, and the overal runtime is totally different.
That is a wrong association really.
Even in the really old versions of GlassFish and JBoss such an admin panel was just an extra (I hate them too, btw).
You could always, Tomcat style, just copy your .war to a deployment folder. If you wanted, you could also zip up GlassFish with the war already in that folder and deploy that.
> registering EJBs with deployment descriptors
That was required for the last time in J2EE 1.4, from 2003 or so. Already in Java EE 5 from 2005 that wasn't necessary anymore. Also don't forget that spring beans needed to be registered in very similar deployment descriptors (huge xml files) just as well.