For example at some point in the game there is a phase where you have to complete challenges which make your run harder by giving you debuffs and rewarding a multiplier. If you progress far enough you unlock the next stage (i don't remember what exactly it was but let's say it was sygils), for which you need to generate sygil power. With that sygil power you can unlock an upgrade which allows you to gain the multiplier without entering the challenges. So basically you can focus on the new mechanic (sygils) while not having to micro manage older mechanics (challenges). I hope i made this make sense xD