how to get rows related to same table through many to many relationship - Laravel

I have a model called Products, and I need to return the related products to the view. So I created another model called Category, and the relation is many-to-many.

I managed to get the related products but each with a category attached to it which is not quit good, and this my code:

$categories = Product::find($id)->categories;
$products = new Product;
$products = $products->toArray();
foreach ($categories as $cat) {
    array_push($products, Category::find($cat->id)->products);
}
return $products;

Is there a better way to do that ?

I did it using regular SQL query and here is the code hoping for helping someone

$catIDs = DB::table('product_category')
            ->select('category_id')
            ->where('product_id', $id)
            ->pluck('category_id');

$productsIDs = DB::table('products')
                ->select('product_category.product_id')
                ->distinct()
                ->rightJoin('product_category', 'products.id', '=', 'product_category.product_id')
                ->whereIn('category_id', $catIDs)
                ->pluck('product_id');

$relatedProducts = Product::with('firstImage')
                        ->whereIn('id', $productsIDs)
                        ->where('id', '!=', $id)
                        ->inRandomOrder()
                        ->get();