I think hedonism is a valid personal choice(if it's a culture-wide beneficial choice -- that's debatable), there's no need to paint other choices black(not saying you were doing directly).
Experiencing in myself and other what you call the "relationship escalator" -- I can assure you it's not driven by hedonism, it's just a functional necessity, at least in the vast majority of cases and history(sure there can be people doing it to brag on social media).
To me it seems that the term "relationship escalator" is pejorative and that you were conflating it with the "hedonic treadmill" and somehow contrasting it with polyamory.
The "hedonic treadmill" effect as described in the wikipedia should apply just as much to monogamy and polyamory or celibacy -- after all, it suggests you will revert to mean happyness after a while.