Move task from Gulp 3.9 to 4 +

Question

I have updated Gulp from 3.9 to 4. I'm not able to run the task. Below is the code before and after migration

Before:

gulp.task('default', [
    'html',
    'assets',
    'javascript',
    'outside-scripts',
    'css',
    'libs',
    'watch'
]);

After:

gulp.task('default', function (cb) {
    gulp.series(
        'html',
        'assets',
        'javascript',
        'outside-scripts',
        'css',
        'libs',
        'watch'
    );
cb();
})

I am not sure what is the problem in the syntax I am using, but the task just starts and ends with no errors either. Probably the series is not being called. Can anyone help me with the syntax please.