I liked to read while lying down and e-readers are an objectively better experience. I can never hold a book in a comfortable way - and ereaders are backlit.

The format has been around for 2000 years, so it's pretty well refined.

1500 years for the current bound format. The preceding codices and before that scrolls were much less user friendly.

They were making something that would be recognizable as a book (or booklet) at least as early as late republic, which ties in to my point that the format has been refined a long time.

I think you mean the codex? It was like a book, except the pages were bound on alernating sides. Not the best design, they improved on it in the middle ages. The codex achieved parity with the scroll in 300 AD, so that the modern book format coming just 200 years later means it wasn't around for that long.

Codex is the latin word for book in general.

Yes, but it is used to describe the book like thing that came before the modern book. We love overloading our Latin words.

I like them more as merchandise, especially hardcover, but they do a poorer job of transferring information, storing, searching.