Beautiful illustrations unnecessarily constrained by oversimplified vocabulary. I enjoyed What If? much more than Thing Explainer because What If didn't lower the bar but brought you up to it. Thing Explainer explains various inventions, biological and astronomical occurrences in simple words, limited to a vocabulary of 1,000 words. I did gain some deeper insights into everyday machinery around me, however, I felt the knowledge was too personal.
The language used to explain these concepts were too analogy focused and didn't use the exact terms for these things which are commonly agreed upon so you won't find much use using the analogies from this book in actual conversation. If you have a limited vocabulary and feel anxious when exposed to big words, you might enjoy the simplified approach in this book. This would be a good book for very young children, English language learners or individuals who would find more value from the illustrations than the words.
I loved reading what if and I'm a fan of the xkcd comics. I personally want to try to simplify my communications after being exposed in highly technical and scientific work, which often makes one's vocabulary too abstract. The book would also have detailed illustrations, and I learn best visually, so I will be able to pick up a deeper understanding of some of the concepts explained in the book.
โBy choosing the right words, you can take an idea that's happening in your head and try to make an idea like it happen in someone else's. That's what's happening right now.โ Randall Munroe