Description
I dug a lot it Symfony internals lastly and the name converter stack was very costly. I reduced it a lot with #35041... Then I realized than I don't need at all a name converter.

The default one is MetadataAwareNameConverter, that allow a fallbackNameConverter. But the fallback is called ONLY after having grab all the metadata, checked for a SerializerName. I never saw a project using this attribute, and it troubles me that it costs so much. So just giving a simpler NameConverter as fallback is not enough because the worse already happened.

I tried another way: replacing MetadataAwareNameConverter completely. It seems to work flawlessly and gives me a 11% performance improvement (AFTER the previously mentioned patch, so more than a 25% gain from master)

<?php
namespace Lib\Core\Serializer\NameConverter;

use Symfony\Component\Serializer\NameConverter\NameConverterInterface;

/**
 * Do nothing name converter
 */
class NullNameConverter implements NameConverterInterface
{
    public function normalize($propertyName)
    {
        return $propertyName;
    }
    public function denormalize($propertyName)
    {
        return $propertyName;
    }
}

services:
    serializer.name_converter.metadata_aware: '@Lib\Core\Serializer\NameConverter\NullNameConverter'

Questions:

• Did I miss something that I could break with that?
• Should a simpler Name Converter should be added in Symfony?
• Should it be the default? Or as least purposed by default
• Maybe add a pass somewhere "hi you are not using any SerializerName and you didn't provide a NameConverter fallback, switching to NullNameConverter"?