In addition Network airlines need to be able to manage connecting flights, including those onto other airlines (either codeshared or not). In order for the systems to work they need to follow the industry protocols that were set up some decades ago. (And changing them is subject to the lowest common denominator principle).
In practice I think the maximum is more like 39 or 40 hours, but that is for the departure of the final connecting flight from the time the transaction is initiated. For the first departing flight it is 23 or 24 hours.
The LCCs don't interline. They don't follow the industry protocols.