order by JSON data type postgres

You put asc in the fieldname. There’s no key named value asc in the json, so data ->> 'value asc' will always return NULL.

You actually want:

select * from table ORDER BY data->>'value' ASC 

to match the json, possibly even:

select * 
from table 
WHERE data ->> 'name' = 'stuff'
ORDER BY data->>'value' ASC