Now you might argue that the data either doesn't support the claims made, or you might doubt its legitimacy, but instead of providing a reason you just told me that it should be obvious why the book is nonsense. That doesn't really give me a lot to engage with and I'm not going to try to make your arguments for you.
For me the Book had its intended effect. It argues that the climate movement, as it gained mainstream popularity, also lost its ability to convey nuance in favor of projecting a strong "we are heading towards certain doom" message. This helped grow the movement, but is also responsible for a lot of young people feeling completely hopeless. That's certainly something I could heavily relate with before reading the book. The book then goes on to highlight areas where the world has made much bigger progress than I would have thought. For me this turned a feeling of intense hopelessness into one of motivation.
So was the Book meant to make me feel good? Sure. In that sense I guess you can call it a feel-good book. Were the claims unsubstantiated and "without any evidence to support" them? Certainly not.
Being pragmatic is not hopelessness. You have to admit what the problems are, and the book does not do that.