who still uses maven? who would prefer xml files over build scripts? (ok… fine, big timers like RedHat definitely do, or at least, have never taken/don’t want to take the time to upgrade lol)

Simple: Gradle doesn't work well with inherited projects. If you have a family tree of projects, maven always wins. Lowers complexity, integrations are easier, bom are better integrated, smaller size of ~/.m2 (by literally gigabytes) and no surprises with classpath loading order. It's not about stupid xml or stupid groovy, it's about complexity of managing single parent project, 200 children and 150 more grandchildren and having them working out of box. More than 12 years of using Gradle, I've never it seen working well outside of Android projects (and it still needs Java7 right?).

End users for gradle are corporations: Google and IntelliJ. Maven has been developed for developers and technical project managers. My projects from ~2000s developed in Ant still compile and work, Maven projects from 2010s still work and compile... can't say that about an Android project from 2014. It doesn't even compile and there's no backwards compatible way to use or upgrade Gradle (from 2.4). To me, gradle is worse than npm ecosystem and we did it all to ourselves.