Complex sentence: Remittances are playing an increasingly large role in the economies of many countries, contributing to economic growth and to the livelihoods of less prosperous people (though generally not the poorest of the poor).
Split into simpler sentences: Remittances are playing an increasingly large role in the economies of many countries. They contribute to economic growth and to the livelihoods of less prosperous people (though generally not the poorest of the poor).