GIMP has a Python console, and several built-in plug-ins are written in Python: https://docs.gimp.org/3.2/en/gimp-filters-python-fu.html

We want to make macros simpler (some of the work I helped out with for GIMP 3.0 was to lay the groundwork for automated/recordable operations), but as with all the things on our roadmap it takes time and developers.