Why does count always return 1?

Question

PostgreSQL

Why does count together with group by always return 1?

select count(*) as aggregate from "products" group by "products"."id"

Answer 1

What information would you like to receive with a request?

Answer 2

Probably because id is a unique field, and when grouping, exactly one is obtained.
But this is not accurate (you did not show what kind of plate you have).