In short, IELTS is not something that tests how robot-like you are!
It tests your critical thinking abilities and how well you can interpret the information given. Also, succeeding in reading largely depends on strong grammar. It is not only words and epressions that give the whole meaning, tone, and purpose of the text. Grammar also plays a critical role in that. That is why I always want to slap the faces of those who say that grammar is not that important in IELTS. Yes, grammar may not be very importanat as long as you want to get 5.5 or 6. If you are happy with those scores, then don't learn grammar deeply, get your 5.5 and never come near to IELTS again!
Xullas, grammar muhimmas degan gapni yig'ishtireylik, yaxshilar!