For example, experienced chess players losing repeatedly to a complete beginner because they're used to playing against stronger and stronger opponents as they were gaining their experience. I've seen it happen often, and it's happened to me too.

Are you sure you aren't just remembering outliers or some other explanation? I've had superficially similar experiences but as far as I can tell, it was due to a simple lack of thinking on my part when playing against the very weak players.