Apparently, the drop rate is higher than we think because the game rolls several times when you open a chest so in theory the 1 in 10000 rate is if you want a specific one. Silvers have a higher chance and I assume CEs have an even higher chance.

However, I agree. The drop rate is abysmally low and there is no pity system of any kind to slowly grind our way to them either besides farming gil.