A film is almost never shot in the order the audience will watch it. The schedule is assembled around the costs that cannot be moved, and narrative order is the one variable with no cost attached.
Locations are booked as blocks
Access to a location is negotiated for a period, and moving a production in and out means transporting equipment, dressing the space and lighting it from scratch.
Every scene set in that location is therefore shot while the unit is there, regardless of where those scenes fall in the story.
Returning later costs a second full setup and a second negotiation, which is why a location revisit is one of the more expensive items a schedule can contain.
Cast availability is the second fixed constraint
Actors are contracted for defined periods, and a performer available for a limited window has all of their scenes clustered into it.
Where several actors have overlapping but non-identical availability, the intersection defines when their shared scenes can happen, and everything else is arranged around that.
The schedule is effectively solved as a constraint problem, with story order treated as the flexible element because it costs nothing to break.
Light and weather cannot be rescheduled
Exterior scenes depend on conditions that occur at particular times and cannot be manufactured cheaply at scale.
Scenes requiring a specific quality of light are placed where that light occurs, and shooting them out of order is unavoidable rather than convenient.
Cover sets exist for the same reason, giving a unit interior work to move to when conditions make the planned exterior impossible.
Continuity replaces chronology
Because the story cannot supply the ordering, a separate department tracks the state of everything across scenes: costume, injuries, props, the level in a glass.
Continuity notes and reference photographs allow a scene shot on the first day to match one shot two months later that immediately follows it.
This is why continuity is a full-time role rather than an afterthought. It is the only mechanism keeping a non-chronological shoot coherent.
The cost falls on the performances
An actor may play a scene's emotional consequence before playing its cause, and has to construct the arc internally rather than experiencing it in sequence.
Directors compensate by tracking emotional level explicitly, discussing where a scene sits on that scale before each take rather than relying on continuity of feeling.
Where budget permits, the most demanding sequences are sometimes scheduled in order despite the expense, which shows how real the cost of the usual approach is.