I haven't worked in the US; and - have not yet worked in a company where such employees exist. Some are slower, some are fast or more efficient or productive - but they're all, everyone, under the pressure of too many tasks assigned to them, and it's always obvious that more personnel is needed but budget (supposedly) precludes it.
So, what you're describing is a mythical situation for me. But - US corporations are fabulously rich, or perhaps I should say highly-valued, and there are lots of investors to throw money at things I guess, so maybe that actually happens.
No, it's the same in the US, too. I don't know what these mythical companies are where people are saying 50% of the workforce does nothing, but I've never seen such a place. Everywhere I've ever worked had way more projects to get done than people available to do them. Everyone was working at capacity.
So, what you're describing is a mythical situation for me. But - US corporations are fabulously rich, or perhaps I should say highly-valued, and there are lots of investors to throw money at things I guess, so maybe that actually happens.