The Wizarding World was an enchanting one, with various kinds of beings and magic. While Harry Potter was full of powerful wizards and witches like Albus Dumbledore and Rowena Ravenclaw, not everyone was created equal. The Wizarding World was full of weaker wizards who were either deficient in magical ability, morals, or character, or all three.
Source:https://www.cbr.com/harry-potter-weakest-witches-wizards/