Why was The Last of Us 2 delayed so many times?

Anticipation surrounding The Last of Us: Part 2 seems to have been going on for years. Naughty Dog got gamers excited since its first look back in 2017 - a return to its brooding vision of a post-apocalyptic world ravaged by a mutated strain of fungus that turns humans into terrifying zombies. But gamers have had to wait. A reunion …