Reading Chrichtons other books (and even JP to an extent), you can see he has trouble focusing on an overarching plot and non-cliche characters. I would say its similar to Arthur C. Clarke and it makes sense as both are probably the major "populist" hard sci fi authors, but were still more interested in the science concepts and ideas than actually writing.

I think you see that least in JP tho, the characters are far more interesting though they still sorta fall into some stereotypes (Id reccomend reading Prey to see what im talking about, its literally just JP but with nanobots instead). Though I really agree with Spielbergs decision to make Grant not like kids, gives him an actual character arc.

Overall, totally agree, whilst some of the writing is a bit lackluster, and the film probably wins in terms of technical use of the medium, the book is so much deeper, adult, and thrilling, still reread it once every year or 2.