Exactly my question @Sergio B. D.! I don't get it, obviously. In my European country every is supposed to and also expected to pay for their own meal unless it is some kind of gathering where the host announced beforehand that everyone is invited. I personally think that this take saves so much trouble! ...as I've never came across the "but I paid this and they paid that" struggle in my country. What I should also add: servers make indeed a living wage (even if not great) and have no problem to do the math.

Because sometimes it's easier, and often it doesn't make a big difference as long as everyone consumed food/drinks in the same price range. We do this a lot, unless someone ordered much more/more expensive food/drinks than the rest

Many times going out with friends we've split the bill, but, as friends, we respect each other and order stuff that costs more or less the same. If someone wants to order something significantly cheaper or more expensive, they'd let the others know and pay separately. Same if anyone brings dates/partners/other friends - bill is split by number of people eating.

We often do this with friends because it's easier and quicker, but we do this when we're aware there will not be a huge difference

exactly . i didnt understand how he subsidied her at the beginning like what kind of paying they were doing. splitting a bill in two while 3 ppl were eating is a non sense to me, dont know if it is common in the US. I would feel embarassed if men were splitting a bill for my food as if i was totally incompetent. in my country everyone pays what they ordered. if they are family each family pays what they ordered. unless there is a person who says at the beginning that they are inviting and therefore paying for all. you either calculate at the table when the bill arrives, you put tge money at the table for the waiter to collect it or everyone goes to the counter and says to the waiter what they are paying for so that the waiter scratches the items from the bill. the last person to come paying will have to pay the remaining part of the bill so if you are drunk or rude and leave a lot of unpaid items it is not fair but that is another story. you should choose your company wisely

It's always the AH who's bill is much higher than everyone else's bill. They propose splitting the bill so their higher bill will be spread among everyone else. OP needs to find better friends.