Original comic Thanos is in love with Lady Death so he just wanted to present the death of half the universe to her.
In the movie situation, while this is not presented, if he were to simply double the resources, there would be no problem to be solved - Thanos would be a good guy instead of a maniac.
In the movie situation, while this is not presented, if he were to simply double the resources, there would be no problem to be solved - Thanos would be a good guy instead of a maniac.