> Is there any part of the world you can have a six top with individual checks when you didn't tell them up front to split the bill?
Most restaurant point of sales systems in the US handle that pretty well. They put down what seat an item was ordered from, and it covers everything except shared items like appetizers. That's been pretty common for a couple decades, and not just at chains, also at local places (if they had a POS system and weren't doing it with paper still, but good servers know how to notate that well, too).
"They" being the waiter or waitress, of course. Good ones can navigate complex bill splitting arrangements and even better can manage awkward interactions like one person quietly paying for another's dessert or covering an appetizer for the table, know the menu not only by memory but also can recommend dishes that the guest may prefer, and generally make the dining and ordering and paying experience better.
Bad restaurants think they can replace those skills with a QR code on the table optimized for the lowest common denominator.