Whether a show is meant to be simple or complex, there’s no real excuse for removing SO MUCH from the characters when translating one show into another.  Teen Titans GO! is shown to be a follow up series to Teen Titans, and makes reference to that more than once, so the loss of character, depth, defining characteristics, features, and everything that actually makes a character good or memorable is inexcusable.  This progression is like removing someone’s frontal cortex and most of what’s left of their left hemisphere.  They might still function to some degree, but it is a sad, pale imitation of something that was whole and great.