What is the format of the output data in APIs to use?

There are API and a conflict of developers.
From table usermeta API outputs a response in the format

object(stdClass)[165]
 public 'data' => 
 array (size=2)
 0 => 
object(stdClass)[167]
 public 'type' => string 'meta' (length=4)
 public 'id' => string '31' (length=2)
 public 'attributes' => 
object(stdClass)[168]
 public 'key' => string 'social_id' (length=8)
 public 'value' => string '123' (length=3)
 public 'user_id' => int 2
 public 'site_id' => int 2
 public 'links' => 
object(stdClass)[169]
 public 'self' => string 'https://example.com//metas/31' (length=29)

With such data difficult to work with one group, because to get the simple value -> key, you need to seek him more in response. Another group proposes to use the format

object(stdClass)[165]
 public 'meta' => 
object(stdClass)[167]
 public 'social_id' => 
object(stdClass)[168]
 public 'id' => int 31
 public 'value' => int 123
 public 'user_id' => int 2
 public 'links' => string 'https://example.com//metas/31' (length=29)

But it all depends jsonapi.org but the work with the usual data as a 1 value, turns into a dance around the standard. Perhaps both sides are wrong and need to use another format to get such a response?
Or someone right?
The table has the structure id, user_id, site_id, key, value