I don't know if this has been said, or it might not fit the setting or lore with the way QI is, but having the elements be more in a cycle, going in a circle, than randomly selected, could be better in a sense to predict the future through patterns. I say this because I just had to start a new incarnation like 50 times because the earth/stone element inheritance did not appear, and I already had all the others. I understand it might be just me who is saying this, and if it is difficult to implement or would mess with the laid out story, then I also understand it being deliberately random.
Viewing post in Cycle of the First Dawn comments
I'm leveling up my elemental affinities and I can tell you that there is a cycle, like I manage to level them up without having a gap too wide between them, but I'm late in the game so I can't remember if it was always like this, anyway I remember that I struggled getting the last inheritance, just wait a bit
I remember checking the save data (before the save format change), the game seems to use an element bag system where every life selects one element from the ones not yet selected during the cycle. So if you miss an element, you will at most have to wait for 19 lives since the worst that could happen is missing the element when it's the first element of the cycle and only getting it again as the last element of the next cycle.