Question about jsonb and data structures

Hello,

I have been playing with Postgresql recently with a large table and I have
started looking at reducing the number of rows in that table.
One idea to reduce the actual size, I thought I would "compress" the data
structure into a JSON object (more on that later).
The table is pretty straightforward in itself
other_id integer
type_id integer
label_id integer
rank_id integer
value real

and the goal is to move to a data structure where we have
other_id integer
value jsonb

There are many things in the table that is not optimal for legacy reasons
and I can't just get rid of them.

I looked at several json object data structure to see if I could make it
work notably
[{"type":1,"label":1,"rank":1,"value":.5},{"type":1,"label":2,"rank":1,"value":.25}]
{"1":{"1":{"rank":1,"value":.5},"2":{"rank":1,"value":.25}}}

For better or worse, the first one would be the best for me as I can do a
simple query like this using the GIN index built on top of value:
SELECT *
FROM mytable
WHERE value @> '[{"type":1,"rank":1,"label":2}]'

Effectively, I would want to extract the value corresponding to my
condition using simple SQL aka not having to write a function extracting
the json.

The experiment on the second data structure shows that it is not as
convenient as I may need to perform search on either type, label, rank and
various combinations of the fields.

Am I missing something?

Thanks in advance,
Emilie Laffray