I'm doing the following exercise:
Question 67
Table: Products

+---------------+---------+
 | Column Name   | Type    |
 +---------------+---------+
 | product_id    | int     |
 | new_price     | int     |
 | change_date   | date    |
 +---------------+---------+

(product_id, change_date) is the primary key of this table. Each row of this table indicates that the price of some product was changed to a new price at some date. Write an SQL query to find the prices of all products on 2019-08-16. Assume the price of all products before any change is 10. The query result format is in the following example: Products table:

+------------+-----------+-------------+
 | product_id | new_price | change_date |
 +------------+-----------+-------------+
 | 1          | 20        | 2019-08-14  |
 | 2          | 50        | 2019-08-14  |
 | 1          | 30        | 2019-08-15  |
 | 1          | 35        | 2019-08-16  |
 | 2          | 65        | 2019-08-17  |
 | 3          | 20        | 2019-08-18  |
 +------------+-----------+-------------+

Result table:

+------------+-------+
 | product_id | price |
 +------------+-------+
 | 2          | 50    |
 | 1          | 35    |
 | 3          | 10    |
 +------------+-------+

This is the solution given by other people:

-- Solution
with t1 as (
select a.product_id, new_price
from(
Select product_id, max(change_date) as date
from products
where change_date<='2019-08-16'
group by product_id) a
join products p
on a.product_id = p.product_id and a.date = p.change_date),

t2 as (
select distinct product_id
    from products)
    
select t2.product_id, coalesce(new_price,10) as price
from t2 left join t1
on t2.product_id = t1.product_id
order by price desc

And here is my solution. I tried to find others solutions on the internet, but all of them are in a very complicated way, why nobody did it this way. Could you please let me know if there is anything wrong with my solution?

SELECT
     t.product_id
    ,CASE
         WHEN t.change_date <= '2019-08-16' THEN t.new_price 
         ELSE 10
     END AS price
FROM 
(
    SELECT
         product_id
        ,new_price
        ,change_date
        ,RANK() OVER
         (
             PARTITION BY product_id 
             ORDER BY change_date DESC) AS rk 
    FROM products
) t
WHERE t.rk = 1