2019 will be the first year since 1999 where there is no active LEGO constraction theme (that we know of so far, there could maaaaybe be a summer theme, but I doubt it).
That means something. G2 tanked horrendously, Hero Factory bled out slowly as its advertising budget was cut down harshly year-by-year. Superhero Ultrabuilds were short lived. Chima ended and its constraction subtheme was handicapped in its final wave and only saw limited release. Knights Kingdom was canned, Ben 10 got like one wave. Star Wars constraction lasted for a while, admittedly, but petered out into relatively simplistic template builds instead of doing anything truly original or out-of-the-box before ultimately having planned sets canceled despite pictures and data being released of them via catalog leaks.
Constraction has been bleeding for several years now. That's not to say it can't be saved, or isn't worth saving, but the primary logic behind our decision to move forward with our "BIONICLE G3" project using system rather than constraction is because we firmly believe BIONICLE would have a stronger chance to sell well and actually get decent marketing behind it if it were a system theme.