Maven is declarative. Once you know how to build and deploy one repository you can do it in any other. Including projects started a decade ago. Five commands is all you need to use it. It's trivial to have a monorepo with the classical 3-tier pom file structure.

It takes a 2/3-of-your-screen plugin configuration to build a Scala project. And you can simply copy that configuration without even thinking about it to another service.

I believe that making the "<dependency>" declaration a one-liner would fix 80% of what's wrong with maven :)

Every single Gradle project I have worked with has its own structure. Which happens even across repositories owned by the same team. There are DSL flavors (Groovy and Kotlin), both are actually used and differ slightly. The wrapper. Its storage is based on Ivy, not Maven so you double the number of Internet replicas on your HDD. But it's still better than SBT ;)