"it takes you one day of being sick or out of form and all the work of 7+ months is gone out of the window"
this has been the sentiment of most pros and some analysts, for the team losing ascension
but for me, this exact thing happens in tier 1 for champions as well. and thats what makes the stakes so high, thats what makes it so fun to watch.
the same is in football, even harsher, one bad day and you have to wait 4 years. (also one of the reasons why UCL "sounds" tougher than a normal league, where you are allowed off days(games)).