What if they find the answer themselves or the question has been aswered. You can edit the question to say it's been answered, but some people bump these year old questions with answers because of their ignorance.
Pokemaster already responded to this a while ago.
This is how closing worked originally, but people kept closing questions incorrectly. For example they closed a question as soon as they got an answer (whether or not it was right). The reason we have closing is so users know that their question is against the rules and it doesn't just disappear.
https://pokemondb.net/pokebase/meta/67581/suggestion-close-your-own-question