Gulp doesn't create folder, what's the problem?

Question

gulp.js

Dear experts, I can't understand what I'm wrong about according to GULP.
Setting up gulp.js
I decided to check how folders will be created and how files will be transferred.
But I did not see the expected result.
It will sit for more than an hour, checking for errors and never found a single one ...
Here is the code:

let project_folder="dist";
let source_folder="src";

let path = {
    build:{
        html:project_folder + "/",
        css: project_folder + "/css/",
        js: project_folder + "/js/",
        img: project_folder + "/img/",
        fonts: project_folder + "/fonts/",
    },
    src:{
        html: source_folder + "/*.html",
        css: source_folder + "/scss/style.scss",
        js: source_folder + "/js/script.js",
        img: source_folder + "/img/**/*.{jpg, png, svg, gif, ico, webp}",
        fonts: source_folder + "/fonts/*.ttf",
    },
    watch:{
        html:source_folder + "/**/*.html",
        css: source_folder + "/scss/**/*.scss",
        js: source_folder + "/js/**/*.js",
        img: source_folder + "/img/**/*.{jpg, png, svg, gif, ico, webp}",
    },
    clean: "./" + project_folder + "/"
}

let { src, dest} = require('gulp'),
    gulp = require('gulp'),
    browsersync = require("browser-sync").create();

function browserSync(params) {
    browsersync.init({
        server: {
            baseDir: "./" + project_folder + "./"
        },
        port: 3000,
        notify: false
    })
}

function html() {
    return src(path.src.html)
        .pipe(dest(path.build.html))
        .pipe(browsersync.stream())
}

let build = gulp.series(html);
let watch = gulp.parallel(build, browserSync);


exports.html = html;
exports.build = build;
exports.watch = watch;
exports.default = watch;

I can not find the root of evil ...

The issue was resolved.
If you never know someone will come across, like me:
The name of the folder is "src", the setting is registered through "#", and in the gulp file I registered without a lattice. That was the problem.
In other words, you had to copy the entire folder name into gulp.

Thanks to all.