jsonb_each_text(jsonb) returns jsonb, not text
jsonb_each is not jsonb_each_text

No, you're calling jsonb_each and you're referencing the docs for jsonb_each_text It shows 

On \dfS json_each_text,

      Name       | Result data type |              Argument data types              |
-----------------+------------------+-----------------------------------------------+
 jsonb_each_text | SETOF record     | from_json jsonb, OUT key text, OUT value text 
 jsonb_each      | SETOF record     | from_json jsonb, OUT key text, OUT value jsonb 


Making that adjustment to call jsonb_each_text

SELECT *, pg_typeof(key) AS type_key, pg_typeof(value) AS type_value
FROM jsonb_each_text('{"2": "-200.08"}');

 key |  value  | type_key | type_value 
-----+---------+----------+------------
 2   | -200.08 | text     | text