Let us not forget that pension and welfare money is not a dead loss. It does not just evaporate. It all gets spent.
If the products purchased are manufactured overseas, however then I do grant that deficits racked up via welfare compound the problem of our import/export imbalance (aka current account deficit, if I read this thread rightly).
Let us also not forget, that, when it was dreamed up, most of those who retired at 65 lived only to age 70 (men), on average. Up to 51 years of paying in, for only 5 years paying out. Those who died prematurely (50s not uncommon, in some heavily-polluting industries) probably helped balance the costs of the ones who lived well beyond age 70.
Well, in theory, at least. Real-life played out very differently and government actuaries were decades too slow in responding to increasing lifespans (averages respond slowly, in a large dataset). Bumping up retirement ages, incrementally was the response; diddling some out of a year or two's payout, although full salary, instead, should have made up for such (notional) losses.
Well done, the NHS, for granting us decades of extra time with our loved ones but it has irreversibly changed the economic climate of this country.
Meanwhile, a lower minimum wage for under-25s. Just what they need when they're trying to start a family. Do we want our own kind to 'breed' successfully or do we want to inhibit them?