Gulp Sass v4 not creating css file - gulp

Question

I'm using gulp version 4 in my project and I want to compile my scss file to css file. But gulp not creating any css file.
My gulpfile.js
// Initialize modules
// Importing specific gulp API functions lets us write them below as series() instead of gulp.series()
const { src, dest, watch, series, parallel } = require('gulp');
// Importing all the Gulp-related packages we want to use
const sourcemaps = require('gulp-sourcemaps');
const sass = require('gulp-sass');
const concat = require('gulp-concat');
const uglify = require('gulp-uglify');
const postcss = require('gulp-postcss');
const autoprefixer = require('autoprefixer');
const cssnano = require('cssnano');
const browserSync = require('browser-sync').create();
var replace = require('gulp-replace');
// File paths
const files = {
scssPath: './assets/scss/**/*.scss',
jsPath: './assets/js/**/*.js'
}
// Sass task: compiles the style.scss file into style.css
function scssTask(cb){
return src(files.scssPath)
.pipe(sourcemaps.init()) // initialize sourcemaps first
.pipe(sass({ outputStyle: "expanded" }).on('error',sass.logError)) // compile SCSS to CSS
.pipe(postcss([ autoprefixer(), cssnano() ])) // PostCSS plugins
.pipe(sourcemaps.write('.')) // write sourcemaps file in current directory
.pipe(dest('./dist'))
.pipe(browserSync.stream());
// put final CSS in dist folder
}
// JS task: concatenates and uglifies JS files to script.js
function jsTask(){
return src([
files.jsPath
//,'!' + 'includes/js/jquery.min.js', // to exclude any specific files
])
.pipe(concat('all.js'))
.pipe(uglify())
.pipe(dest('./dist')
);
}
// Cachebust
var cbString = new Date().getTime();
function cacheBustTask(){
return src(['index.html'])
.pipe(replace(/cb=\d+/g, 'cb=' + cbString))
.pipe(dest('.'));
}
// Watch task: watch SCSS and JS files for changes
// If any change, run scss and js tasks simultaneously
function watchTask(){
watch([files.scssPath, files.jsPath],
parallel(scssTask, jsTask));
}
// Export the default Gulp task so it can be run
// Runs the scss and js tasks simultaneously
// then runs cacheBust, then watch task
exports.default = series(
parallel(scssTask, jsTask),
cacheBustTask,
watchTask
);
My Project Hiererchy
myProject
|_ assets
| |_ css
| |_ scss
| |_ js
|_ index.html
|_ node_modules
|_ gulpfile.js
|_ package.json
and when running Gulp
[14:27:33] Using gulpfile F:\blog-project\infonites\gulpfile.js
[14:27:33] Starting 'default'...
[14:27:33] Starting 'scssTask'...
[14:27:33] Starting 'jsTask'...
[14:27:33] Finished 'scssTask' after 64 ms
[14:27:37] Finished 'jsTask' after 4.36 s
[14:27:37] Starting 'cacheBustTask'...
[14:27:37] Finished 'cacheBustTask' after 7.71 ms
[14:27:37] Starting 'watchTask'...
And after running gulp my project hierarchy
myProject
|_ assets
| |_ css
| |_ scss
| |_ js
|_ index.html
|_ dist
| |_ all.js
|_ node_modules
|_ gulpfile.js
|_ package.json
This is my final output after running gulp task. I don't understand why gulp running js task but not css task.