These are among my favorite books, and I've read thousands of books. It was written in the 90s or early 2000s, so the tech that was so futuristic now exists everywhere (IoT). You question believability? The tech is so not "just way over acceptable", much of it already exists. If we can suspend our belief to read about aliens, hobbits, magical schools, talking animals, etc., this hardly stretches the imagination at all.

Don't let this guy stop you from reading these awesome books! I recently re-read it, and the first few chapters are pretty tough because it lays out all the tech premises. Stick with it. The plot will keep you engaged, and the storytelling is supurb