[fjtorres]

PDF wasn't designed as a reading format. It was designed to capture complex format print documents for archiving. It turned out by useful for transmitting documents via email. Reflow and resizing were retroactively grafted when ebooks first became a commercial product but it's a poor fit because pdf's primary focus (hardwired into the format) remains page design. After 30+ years the best way to read a pdf is still to print it.