Why most of the Shia Scholars have said that it is not permissible to marry with Ahle kitab?
While Quran says it is permissible

"And ˹permissible for you in marriage˺ are chaste believing women as well as chaste women of those given the Scripture before you—as long as you pay them their dowries in wedlock, neither fornicating nor taking them as mistresses."

(Surah Maida Ayat 5)

Our scholars are not sure if we currently have true Ahlul Kitab. Hence their rules on the marriage