If Catholicism is about self sacrifice and giving to the poor then why does the Vatican have to keep so much wealth and high value assets?

Just wondering why the Vatican needs all that stuff? If it because it is holy surely the poorer people would need it closer to them to help spread the wealth? Isn’t the point of Catholicism to love other Catholics and help them in their time of need and self sacrifice and giving to others? The Vatican could sell them and give the money to the poor, is that not the most ‘Christian’ thing to do with it? To me the wealth of the Vatican simply undermines the values of the Catholic church? Please help me understand this, as an atheist I just don’t get it.
I do understand that they need large buildings to house congregations of people to worship etc. I just don’t understand the pope sat there dripping in gold etc.
This probably applies to other religions too however I haven’t researched it.