Most people actually get paid either weekly or every other week, rather than monthly. So it really still won’t match up properly.

Most people here just intuitively understand how our pay/bills system works, because we are so accustomed to it. I’m not saying this to be flippant or anything but we have basically two types of standard employment job. We have hourly workers, who typically can tell you their hourly rate, but won’t really know what their take-home for a given pay period will be, due to inconsistent scheduling, tips, whatever, so using the whole year’s income (a number you have to use for taxes anyway, so you definitely know it) makes sense. Then you have people who have fixed hours or who are paid salary, and they usually describe their compensation package annually, because the specific monthly amount doesn’t matter so much as having it consistently, and it’s presented to them by their employer as an annual number because big numbers feel better when all the numbers are pretty small overall.

It makes adequate sense (in an “it functions well enough” sort of way) when you live in it your whole life and are used to it and nothing else, but I can see it being mighty confusing from the outside.