How can Sahih al-Bukhari be relied upon and its authenticity claimed, when Imam al-Bukhari lived 400 years after the death of the Prophet, may Allah bless him and grant him peace?

Imam al-Bukhari passed away in 256 AH, which is 245 years after the death of the Prophet, peace and blessings be upon him. Al-Bukhari did not narrate directly from the Prophet in his Sahih; rather, he narrated from trustworthy shaykhs who possessed the highest degrees of memorization, precision, and trustworthiness, reaching the Companions who narrated from the Messenger of Allah, peace and blessings be upon him. The minimum number of narrators between him and the Prophet was three. Sahih al-Bukhari relies on the precision of the narrators whom al-Bukhari meticulously selected. He would not write down a hadith until he had performed ghusl and prayed two rak'ahs of istikhara. The compilation of the book took sixteen years, and the Ummah accepted it and agreed upon the authenticity of its contents. Imam an-Nawawi said: "The scholars, may Allah have mercy on them, have agreed that the most authentic books after the Glorious Qur'an are the two Sahihs, al-Bukhari and Muslim, and the Ummah has accepted them. Al-Bukhari's book is the more authentic and beneficial of the two." These claims aim to discredit the Sunnah, which clarifies the falsehood of the doctrine of the people of innovation. The questioner is advised to be keen on associating with the people of Sunnah and avoiding the people of innovation.