Seeking Understanding: Why Choose Islam?

As-salamu alaykum. I hope you are all in the best of health and iman. I’m someone who was raised Christian but no longer practices, and I’ve recently started reading the Qur’an to learn about Islam. I have a sincere question from my reading of Surah Al-Imran, and I ask with the utmost respect, seeking guidance from those more knowledgeable. In verse 3:84, it’s stated that Muslims believe in all the prophets and the messages they brought, including those in the previous scriptures, without distinction. Then, in 3:85, it says that if anyone desires a religion other than Islam-complete submission to Allah-it won’t be accepted from them. Throughout the Qur’an, like in Surah Al-Baqarah, it’s emphasized that the message to Prophet Muhammad (peace be upon him) confirms what came before. It even mentions that People of the Book who do good and believe will be rewarded. So, my question is: If the core belief in one God is the same, why is it essential to follow the final message as revealed to Prophet Muhammad (peace be upon him) through the Qur’an, rather than the earlier revelations to prophets like Ibrahim, Musa, or Isa (peace be upon them all)? Why are specific acts like praying salah, fasting in Ramadan, and performing Hajj so important in Islam, when Jews and Christians also worship the same God? What makes the Islamic message unique and complete? Jazakum Allahu khayran for any insights. I’m just a curious soul trying to understand the deen better.