As a Qt application developer, when developing the application, I should only require the minimum of tools that are needed for the job.

Usually that's a C++ toolchain, but for packaging and deployment one would need specialized tools.

For Android Google is recommending using gradle, which is used a build system for their Java / Kotlin applications. C++ is also supported by gradle as seen at Building C++ Applications Sample (gradle.org)

For building Qt applications, we recommend using CMake (qmake, qbs are also popular with developers).

androiddeployqt is generating a gradle file for packaging the application, which works but having to generate a source file for a different build system is a bit an overkill. Here you can see that is possible to package an Android application without gradle: How can I build an Android apk without Gradle on the command line? - Stack Overflow

I have had problems in the past with gradle needing internet access to update itself, or that it needed a newer java runtime version that the one installed.

Having less dependencies would mean having less sources of problems and headaches for developers.