If you’re 1500 and utilize map knowledge, it just means your dynamic game ability is shittier than the 1500 without the map knowledge. You’re both still 1500.
This isn’t sentons where people enter a rating ecosystem entirely separate from the rest of global rating and so there is a sharp disconnect. It’s ladder and you get put against a generally similar level of competency. The illusion that a 700 rated guy that can’t read basic maps will somehow be able to read random maps well is just that, an illusion to explain their rating/losses.