They may even mention it to a co-worker or a supervisor (who will then take credit for it), but typically that is where it ends. One person performs that task much better than everyone else doing the same task, and a small measure of efficiency increases. That employee moves on, does not document that great idea, and departs with it. The supervisor doesn’t quite remember the details of how it was done, and now everyone else doing that task is struggling to reinvent that same wheel.
With ISO, that improvement is documented and incorporated into the process for that task, and everyone benefits. It truly is a mindset that changes a company’s behavior and makes it a better company if done right.