Sql Postgres：表的累积视图

我有一张这样的变更表

CREATE TABLE IF NOT EXISTS changes (
    entity_id TEXT NOT NULL,
    column_id TEXT NOT NULL,
    value JSONB NOT NULL,
    updated_at TIMESTAMP NOT NULL
);

INSERT INTO changes VALUES ('1', 'height', to_jsonb(140), '01-01-2021 00:00:00'::TIMESTAMP);
INSERT INTO changes VALUES ('1', 'weight', to_jsonb(30), '01-01-2021 00:00:00'::TIMESTAMP);
INSERT INTO changes VALUES ('1', 'height', to_jsonb(145), '01-02-2021 00:00:00'::TIMESTAMP);
INSERT INTO changes VALUES ('1', 'weight', to_jsonb(34),'01-03-2021 00:00:00'::TIMESTAMP);


 entity_id | column_id | value |     updated_at      
-----------+-----------+-------+---------------------
 1         | height    | 140   | 2021-01-01 00:00:00
 1         | weight    | 30    | 2021-01-01 00:00:00
 1         | height    | 145   | 2021-01-02 00:00:00
 1         | weight    | 34    | 2021-01-03 00:00:00

我想要获得这张表的累积视图

entity_id  | height | weight |     updated_at      
-----------+--------+--------+---------------------
 1         | 140    | 30     | 2021-01-01 00:00:00
 1         | 145    | 30     | 2021-01-02 00:00:00
 1         | 145    | 34     | 2021-01-03 00:00:00

我当前的查询看起来很有效

SELECT
  entity_id,
  coalesce(change->'height', lag(change->'height', 1, null) over (partition by entity_id order by updated_at)) as height,
  coalesce(change->'weight', lag(change->'weight', 1, null) over (partition by entity_id order by updated_at)) as weight,
  updated_at
FROM (
    SELECT entity_id, json_object_agg(column_id, value) as change, updated_at FROM changes
    GROUP BY entity_id, updated_at
) as changes;

但我不喜欢这里的json_object_agg，我相信有一种方法可以在没有冗余聚合的情况下完成它？我错过了一些使用窗口聚合函数的方法.

UPD.@SelVazi帮助让Query变得更好，但我觉得这不是最终的解决方案.

with cte as (
  SELECT
    entity_id,
    max(case when column_id = 'height' then value::int end) as height,
    max(case when column_id = 'weight' then value::int end) as weight,
    updated_at
  from changes
  GROUP by entity_id, updated_at
)
select
  entity_id,
  coalesce(height, lag(height) over (partition by entity_id order by updated_at)) as height,
  coalesce(weight, lag(weight) over (partition by entity_id order by updated_at)) as weight,
  updated_at
from cte;