Because the book is poorly organized (grouped vaguely by function: "Amplifiers," "Oscillators," "Power Supplies"), you stumble. You look for a tone generator and find a weird transistor astable multivibrator you’ve never seen. That serendipity is lost in modern curated databases like YouTube tutorials or AllAboutCircuits.
For those specifically wanting a vast "handbook" style collection of schematics: The Art of Electronics 1001 practical electronic circuits pdf better