With regard to mental health, I think many schoolchildren were much happier with schools closed, especially those at secondary school so the argument that schools could be kept open for children's mental health doesn't hold much water.
Of course some children are happier out of school - I hated school as a child - but the long term effects of a big gap in education may end up being more far reaching.
But what I meant by mental health is adult mental health. Loss of income resulting in debt, depression, alcohol abuse etc etc.
My point is that unless we continue to get things back to as normal as possible, the effects of Covid are going to be far worse and far reaching than the deaths from the actual virus.