The distribution of wealth is a huge problem, isn't it.
Literal
Abundance [possessive-の] distribution [topic-は] big problem-[assertion-だ] [tag-ね]
豊かさ turns the na-adjective 豊か ('rich') into a noun with the suffix ~さ (making abstract nouns from adjectives). 配分 = distribution/allocation. The final ね invites agreement — suggesting the speaker expects the listener to share the sentiment.