[jacquesm]

You'd think if they are able to reliable set up a contribution scheme that works at scale that they could set up a system to ensure they only pay out to individuals that are still alive.

The possibility of impersonation isn't limited to pension pay-outs but many other things as well. A once-per-year on-site visit would work and would just be a cost-of-business item, and that cost could be lowered substantially by collaborating with other entities who take an interest in such information (banks, governments etc).