-[Splt] Why does Holy Quran Praise Ahl-e-Kitab (JEWS, Christians) ?

Re: Presence of Shirk among sunni and shia muslims

Ever read ayah about trinitarians in Quran?

This ayah is for previous nations who were before Prophet Muhammad(SAW).
**(And whoever seeks religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers) (3:85). **

you’ve missed the ayah before
5:68
(68. Say: "O People of the Scripture! You have nothing till you act according to the Tawrah, the Injil, and what has (now) been sent down to you from your Lord (the Qur’an).‘’ Verily, the revelation that has come to you from your Lord makes many of them increase in rebellion and disbelief. So do not grieve for the people who disbelieve.)

Said bin Jubayr, As-Suddi and others said that these Ayat were revealed concerning a delegation that An-Najashi (King of Ethiopia) sent to the Prophet in order to hear his words and observe his qualities. When the delegation met with the Prophet and he recited the Qur'an to them, they embraced Islam, cried and were humbled. Then they returned to An-Najashi and told him what happened. Ata’ bin Abi Rabah commented, "They were Ethiopians who embraced Islam when the Muslims who migrated to Ethiopia resided among them.‘’ Qatadah said, "They were some followers of the religion of `Isa, son of Maryam, who when they saw Muslims and heard the Qur’an, they became Muslims without hesitation.‘’ Ibn Jarir said that these Ayat were revealed concerning some people who fit this description, whether they were from Ethiopia or otherwise.

They are called People of the Book but it doesn’t mean that they don’t commit shirk.