why my php array don't appears the changes on it - php

Question

hi everyone i'm working on laravel project and for some reason i need to add some attributes to the request using middleware , but my request is nested arrays .
here is the code :
// Middleware //
public function handle(Request $request, Closure $next)
{
$request->json()->add(['created_by_user_id' => Auth::id()]);
$request->json()->add(['user_id' => Auth::id()]);
$request->json()->add(['updated_by_user_id' => Auth::id()]);
$request->json()->add(['deleted_by_user_id' => Auth::id()]);
foreach ($request->json()->all() as &$json_request){
if(is_array($json_request)){
foreach ($json_request as &$item){
$item += ['created_by_user_id' => Auth::id()];
$item += ['updated_by_user_id' => Auth::id()];
$item += ['deleted_by_user_id' => Auth::id()];
}
}
}
return $next($request);
}
it can add the attributes to the top level of arrays ,and when it get deeper it works fine but the attributes are not added to the main request , so when i return request's attributes from the controller to see attributes are arrived i get :
{
"max_price_new": 9999,
"min_price_new": 1111,
"max_price_old": 9999,
"min_price_old": 1111,
"names": [
{
"translation_lang_id": 1,
"category_name": "test9"
},
{
"translation_lang_id": 2,
"category_name": "9تجربة"
}
],
"category_pages": [
{
"page_id": 1
}
],
"category_regions": [
{
"region_id": 1
}
],
"category_photos": [
{
"device_id": 1,
"photo_path": "ite",
"photo_size": 1
}
],
"created_by_user_id": 1,
"user_id": 1,
"updated_by_user_id": 1,
"deleted_by_user_id": 1
}