PL SQL: Why does FIRST VALUE with DESC sort and LAST_VALUE produce different values?

Question

Oracle

Essence of the question. I saw the FIRST_VALUE function with reverse sorting by DESC in the colleagues' script.
I need to rewrite it for another DBMS that does not understand DESC
SELECT distinct account_id,
FIRST_VALUE(amount)over(PARTITION BY account_id ORDER BY payment_date desc)last_payment
FROM kollecto.payments
where account_id in (759318,759320,759322,759324)
order by account_id ;
The question immediately arose: why not use LAST_VALUE with default sorting?
Tried:
SELECT distinct account_id,
LAST_VALUE(amount)over(PARTITION BY account_id ORDER BY payment_date)last_payment
FROM kollecto.payments
where account_id in (759318,759320,759322,759324)
order by account_id;
But the problem is that it returned a very different set of values.
What's the catch here?