A "pension" means an employer-funded pool of money that pays out fixed payments after a certain age. What you're describing exists (somewhat unevenly) in the US, but it's employee funded. The employee must take active steps to contribute, which means they lose part of their income until they retire and there may or may not be employer contributions. People who can't afford to contribute, or put it off for a few years (most people) end up with insufficient funds at retirement, which becomes a social problem.
Those aren't, and never were, pensions. Few pension programs exist anymore, they were (almost) all replaced with retirement accounts starting I don't even know when, but finishing by the mid 1980s. The pension programs were all going bankrupt due to various reasons (bad economy, American industrial collapse, etc) but mostly demographic implosion.
