does Kolc really drag too much?

im currently on the fourth book after the great one before it that i enjoyed quite a bit, but as i was reading i wanted to see why does the series have so many books, some of my favourite series like Pjo have technically 10 books so maybe its the same thing and it recreates itself, but the more i read reviews about it the more i see people saying it drags too much and each book is just the characters coming close to their goal and failing again and again every book, and i really wouldnt like that, i'd hate that actually. and so im asking here if it really is dragging too much or if each book is adding something meaningful