Fasting is not related to being poor or rich. Instead, it is related to seeking the Love and Pleasure of Allah.

Hadith:

Abu Huraira reported that the Messenger of Allah ﷺ said:

Every (good) deed of the son of Adam would be multiplied; a good deed receiving a tenfold to seven hundredfold reward. Allah said: With the exception of fasting, for it is done for Me and I shall give a reward for it (Myself), for one abandons his passion, food and drink for My sake.

Sahih Muslim:2707

If a person does not complete obligatory acts (of ibadah), then he is a grave sinner and is entitled to punishment. In case of failing to carry out obligatory ibadah (without a valid Sharai reason) no excuse shall be accepted.

If a person lives in a place where it is very difficult or impossible to carry out his obligatory religious worship, then it is forbidden (haram) for him to live there. He must move to a favourable place where he is free to carry out his religious duties and ibadah (worship).