On one hand, the concept behind Powerpuff could have worked very well - the Girls being grown up, lost in purpose thanks to life drama, would easily be the base of a great storyline, even though the original series never took itself that seriously.
On the other hand, going by how The CW did it - retconning the original into a fictional cartoon just to make way for some of the new characters, most of the conflicts being overplayed cliches that don't fit the bigger series story, & the many many mentions of real products that no one asked to hear about - it's clear the series wasn't going to be any good, as much as we needed any kind of extension to the franchise (& still do).