Where do things drag?

Genuine question. These are not my Mark-tinted glasses making me biased, but a true confusion. Ive seen a ton of reviews from a wide variety of sources. And many of them agree that this movie could stand to lose a whole half hour, and that there are point where time drags and things could be shortened. Even the reviews from people who loved it say this. Um…WHERE?!? I watched the movie three times in theaters, and the third time I was barely paying attention because i was timing everything on my watch. The slowest moments, like where he’s mapping out the unexplored cave or when he’s doing the initial exploration before he finds the skeleton. These are each less than 6 minute segments before “big” things happen. From when he sees the monster to when he finds the SM-8, that mapping montage is 3 and a half minutes. Are these the “long slogging moments that could be skipped”?? Its only 3 minutes between when he finishes trying to get into the computer files and the voice of Ellie starts talking to him. So can someone genuinely tell me what content people think was “slow” and could be taken out to make the movie better. Every moment I could even slightly see as slow is still giving important information that becomes relevant either soon or for the climax. So can someone please explain what these people mean?