A person who is focused on this life always feels poor because of seeing all that he does not have of it; he is not focused on Jannah, nor believing in it or striving for it.
Since he believes it is he himself who has to do what he can to gather the riches of this world his outlook and behaviour are selfish. Selfishness begets selfishness. Those who are preoccupied with getting the most for themselves induce the same feelings in those around them. Thus, nobody sincere wants to be around a person preoccupied with his worldly life and its achievements.
Such a person gets in life what Allah (subhana wa ta’ala) had destined for them a long time ago, but not Allah’s special blessings to be bestowed in the next life.