Why create new s_defaultSimpleConverters and s_defaultFactoryConverters each time when calling method GetConverter of JsonSerializerOptions?

[dczuo]

runtime/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.Converters.cs

Line 31 in b42188a

private void RootBuiltInConverters()

[huoyaoyuan]

@dotnet/area-system-text-json I had the same question when I viewed the code.