Here's the deal : we have a big product with legacy, and custom code to handle minification, packing, compilation (for less files) for all our front end assets.
We think about using wro4j, but I've come across multiple articles advising to use grunt or gulp instead.
I'm here to find advices about which is the best choice.
With JS advanced beyond just minification, packaging to transpilation and tree-shaking etc there is definitely a plus to using grunt and gulp where such features are supported. In wro4j you have limited choices for processors available. https://wro4j.readthedocs.io/en/stable/AvailableProcessors/
Hence you have to write your own custom processors to support new features in your build process.
Plus, I am an advocate that front-end developers find it easy to understand/edit build processes written in their native language (grunt and gulp use JS) than having to learn Java and Maven to get familiar/working with wro4j
