Why did Prophet Muhammad marry ‘Ā’ishah when she was still so young?

In "Shaīh al-Bukhāri", which is the most authentic book of the Prophet's Hadīths, we find what indicates ‘Ā’ishah's great love for the Prophet (may Allah's peace and blessings be upon him) and we find that she never complained about this marriage.

What is strange is that at such time, the Prophet's enemies accused him with most bitter accusations, saying that he was a poet and a madman; however, none discredited him for such a story and it has never been mentioned except now by some of the prejudiced ones. This story is either something normal that was common among people at that time, as history tells us stories of royal marriages that took place at a young age, like the age of Mary in the Christians' belief, which was close to the age of ‘Ā’ishah at the time she got married to the Prophet, when she was engaged to a man in his nineties before conceiving Jesus. There is also the story of Isabella, the Queen of England, in the eleventh century, who got married at the age of eight, and there are other stories too. [152] Or the story of the Prophet's marriage did not take place in the way they are imagining. http://muslimvilla.smfforfree.com/index.php...https://liguopedia.wordpress.com/.../19/agnes-de-france/...