What I am saying is that when we buy a new sofa we split the expense in two halves, we don't measure each second each of us spend sitting on it so that the split represents EXACTLY our individual usage. Same with groceries, we don't count each grain of rice each of us consume, we are okay with some level of inaccuracy. Anything besides that would be absolute madness.
At the end of the month we still both get a pretty solid idea of our individual expenses no matter who actually paid of an item. For instance my expenses for the month are ¥2200 while last month it was ¥2500, seems like useful data, right? Who cares if one of us made a better deal than they should have on the sofa while the other consumed a few grams of rice more than other?
I am surprised this inaccuracy makes you question the reason of tracking personal finance.
Edit:
> What is the point of all that separating work if you don’t care about it not averaging out?
Maybe that's the source of the confusion, our finances are already separated, there is no extra work separating expenses. There is extra work for expenses we have in common like the sofa or groceries, in which case we do half and half even if that's sometimes inaccurate.
At the end of the month we still both get a pretty solid idea of our individual expenses no matter who actually paid of an item. For instance my expenses for the month are ¥2200 while last month it was ¥2500, seems like useful data, right? Who cares if one of us made a better deal than they should have on the sofa while the other consumed a few grams of rice more than other?
I am surprised this inaccuracy makes you question the reason of tracking personal finance.
Edit:
> What is the point of all that separating work if you don’t care about it not averaging out?
Maybe that's the source of the confusion, our finances are already separated, there is no extra work separating expenses. There is extra work for expenses we have in common like the sofa or groceries, in which case we do half and half even if that's sometimes inaccurate.