Is it reasonable to have grunt/gulp build phases in javascript dev environment

Nowdays it's goes to be very fancy to have grunt/gulp build phases who concatenate and minify and organize javascript code.

And I agree that this is important for production.

But as a developer, I see inconvenience there:

1. additional step to run code (execute gulp/grunt command)


2. hard to navigate in one concatenated files (even worse if it's minified)


3. Build procedure take time, especially if your project quite big and pc not very powerfull

So, is it important to have all that steps for development mode anyway, or will be reasonable to make it a part of release process, and avoid using it during development?