I think the one-star reviews are somewhat harsh.
I have read some terrible books, in my time, for which a 1* review would be appropriate, and this book is way better than those.
That said, yes - the writing isn't as fluid as some JR books. This is partly down to a large number of characters, introduced quite early. Additionally, the plot is quite complex.
Both of these aspects contribute to a narrative that doesn't flow easily, and it did result in me back-pedalling to re-read some sections.
Ultimately, however, it is an interesting plot.
The book opened up once I'd got beyond the halfway point. The plot was clever, and I finished the second half of the book, in a fraction of the time that it took for the first half.
I do have two criticisms of the book. The first is related to the rather cliché references to JRs renowned intuition. There is a bit where a plot-critical notebook is found because JR noticed an off-centred rug. Honestly? What house doesn't have an off-centred rug, or mat etc... And why would tech-savvy criminals rely on a hidden notebook to record vital information, when they are clearly adept at keeping encrypted digital records.
Secondly, this simply isn't a good backdrop to a JR novel. He is a late 90s or early 2000s character. He is a fish out of water in a high-tech 2020s landscape. It's like putting John Wayne in a Star Wars film. A fish out of water. Please relocate JR in early 2000s for the next novel. This is his comfort zone, and where stories flow more easily.
So - I would like to go against the trend, and give a higher rating, but a 3 is fair.