Why are the Marian dogmas necessary?

I'm a protestant that's considering Catholicism. In my research, I've come to believe and accept all of the Marian dogmas that the Catholic church teaches. I love Mary, the Hail Mary has become a favorite prayer of mine and I believe that some protestants are doing harm but slandering her and treating her as if she was simply any other woman. That said, as I no longer have an issue with the dogmas, I am now questioning why does the church make it mandatory to believe them? Doesn't this add more requirements to obtain salvation?

Specifically, why does anyone need to believe that Mary remained a virgin after the birth of Christ or believe that she was assumed into heaven as a condition of being part of the church? If the church believes that there is no salvation outside of her and that the Marian dogmas are a mandatory condition then it feels like the church is adding additional requirements for salvation that are not part of the original gospel of Jesus Christ. Perhaps I'm overlooking something but I don't think the assumption or her perpetual virginity have anything to do with the resurrection, the commandments of Christ, any of the sacraments or any of the teachings from the 12 apostles.

Any resources or reasons to consider their necessity would be appreciated. I'm this close to going all in on Catholicism but this is a significant hang-up for me. I recently heard a voice tell me that I don't need to become Catholic. Trying to discern if it was Satan.