.. which is a contribution based benefit. There's a lot of (deliberate) confusion between pensions and "welfare" benefits, which are generally not available to either immigrants who have not achieved nationality or to overseas nationals.
People should cite more specific examples if they want to claim otherwise.
Of course pensions aren't contingent on being in-country, but I have trouble picturing the same bureaucracy being less anal about other government benefits.
What benefits? I don't know every country in the world, in Germany unless you count retirement as a benefit (which is something you pay for and have to reach a certain age that is ever moving upwards) you don't get any assistance if you're not living in the country.
Benefits aren't collected in cash, they are sent to bank accounts. The beneficiary can be anywhere.
When were you last summoned, or visited at your adress by government officials to verify that you are where you said you'd be?