I feel like this argument is brought up every time Indian government invests in anything. My two cents below with the full disclaimer that I have been fortunate enough to evade poverty most of my life.

I am not saying that the poverty issue and the sheer scale of it, as you mentioned, shouldn't be a top priority but it can't be the only priority. I am from India but have lived in the US most of my life and have to say that looking at both countries, unbounded welfare spending does not seem to solve the issue of poverty and we can't possibly expect that to work against a growing population. It may mitigate the scale of it in the short run but in the long run, investing in the economy seems to be a better way of reducing poverty.

I can't comment much to the merits of doing a manned mission vs other types of space missions but science investment vs poverty is not a great way for any government to prioritize spending. For me, balanced spending is the way to go.