It's not just that, while devaluation alters import prices local prices like rent and service costs don't fluctuate. So a 30% devaluation doesn't make people 30% poorer.
But thanks to your example I see it has more subtleties: it is also a question who to take the money from. Making landlords poorer might be an easy sell to the majority of the population - if the population would have any idea of what is going on, which I doubt.
Services might just go away if they make less money.
Government declares that the arbitrary denominators of value now buy half the number of a different arbitrary denominators of value they did previously.
Because I am a locovore Luddite (for the sake of the argument), everything I buy is made in the country, with materials produced in the country.
How does the devaluation effect me?