Round here, Glasgow, Scotland, areas that are practically walking distance apart can have the same disparity in life expectancy as your futurology may suggest. [https://www.dailyrecord.co.uk/news/scottish-news/men-in-glas...]

That's an extreme example, and the figures have moved since that article was published, but currently a wealthy citizen of Scotland can expect an extra 25% life expectancy compared to a citizen raised in relative poverty.