How to group products by parent category with unlimited descendants?

I have a similar situation.

Here is my code.

public function categories(): HasMany
{
    return $this->hasMany(Category::class)->with('categories')->orderBy('name');
}

public function category(): BelongsTo
{
    return $this->belongsTo(Category::class);
}

public function subCategoryIds(): array
{
    $subCategoryIds = [$this->id];

    foreach ($this->categories as $category) {
        $subCategoryIds = array_merge($subCategoryIds, $category->subCategoryIds());
    }

    return $subCategoryIds;
}

public function subTables(): Collection
{
    return Table::with('category')->whereIn('category_id', $this->subCategoryIds())->orderBy('name')->get();
}

public function tables(): HasMany
{
    return $this->hasMany(Table::class)->orderBy('name');
}

And I get the categories with the tables in the controller.

public function categories(): Collection
{
    return Category::select('id', 'name', 'description', 'category_id')
        ->with('categories', 'tables')
        ->whereNull('category_id')
        ->orderBy('name')
        ->get();
}

public function tables(): Collection
{
    $tables = new Collection;

    if ($this->selectedCategory) {
        $tables = $this->selectedCategory->subTables();
    } else {
        $tables = Table::orderBy('name')->get();
    }

    return $tables;
}

The only problem is that if I have 10 different categories and each one has also 10 subcategories, ... there is a big N+1 problem.

For my project it doesn't matter because there are very few categories, but it can be a problem for a lot of categories.