[georgestephanis]

As someone who has been active with the WordPress community for about fifteen years now, the early documentation and Codex's robust documentation and easy on-ramp for new developers always struck me as one of the main reasons for WordPress's growth over the years. In the early days of the late-aughts, when Joomla, Drupal, and WordPress were all pretty similar in terms of install base, WordPress was just simpler to start with and become familiar due to its abundant documentation.