Your original question listed a few countries, not just China, and my response was a general one. Secondly, my statement clearly says "struggle for food" not starvation.
People are more focused on the daily necessities of life, working so they can buy food as an example. You then also discount my second point, the risks. Social consequences, jail or the death are punishments in some of these countries for being found using apps that are not sanctioned. This would also reduce their use.
While I agree with your question that Nostr would be good for oppressed peoples, I simply state my two points as reasons why it is currently not used.
My feeling is no answer will satisfy you and you're just after an argument. I'll ask you then, can you outline better reasons for its slow uptake in these nations?