And Maven makes writing custom build logic just hard enough to discourage people from doing so, which is a very good thing, from my experience of having worked with Gradle for 5 years or so.

Maybe that is the case if you are working on a project that is large enough to have a dedicated build engineer who stays on top of the Maven situation. But in my experience Maven has been an absolute nightmare to work with for me and others on the teams that I have been on. I don't know how many days have been lost to trying Maven to do one simple thing correctly. And I can tell you that more than once was I eventually so fed up that resorted to using the Ant plugin. That was usually able to solve a problem in five minutes that I had already spent a day on trying to get Maven to cooperate.

That being said, when I switched over to Gradle almost ten years ago, it was still only a marginal improvement, but an improvement nonetheless. Unfortunately, things only seem to have gone downhill from there.

Gradle has support for running and building with different JDK versions (it's not new with Gradle 7 but it's a recent feature).

So it was possible to support building Java 16 projects while running Gradle on a supported Java version before Gradle 7 was released.

https://docs.gradle.org/current/userguide/toolchains.html

When Gradle advocates tell it is faster than Maven, they usually let it off that Maven doesn't require a backgroud daemon eating away GBs to be fast.