This comment is hard to address without understanding the details of your project, but I will at least say that it doesn't mirror my experience.

Generally, I would use the same tools (e.g. ./gradlew build or docker build) to build stuff locally as on CI, and config params are typically enough to distinguish what needs to be different.

My CI scripts still tend up to be more complicated than I'd like to (due to things like caching, artifacts, code insights, triggers, etc.), but the main build logic at least is extracted.