Venues that host more than one sport are sold on flexibility. The practical measure of that flexibility is how many hours it takes to change from one configuration to another.
The seating moves, not just the field
Different sports need different distances between the sideline and the first row, and premium seating is priced on that proximity.
Retractable lower bowl sections, rolling risers and demountable seating decks exist to move those rows, and they are the slowest part of any conversion.
Each system has its own drive mechanism, alignment tolerance and safety inspection, and none of them can be rushed without risking a stuck section.
Surfaces change on a different timeline
Where a venue swaps between natural turf and a hard floor, the surface change itself can be quick, since panels and covers are designed for speed.
Where an overlay field of real sod is installed, the timeline stretches to days because the sod needs laying, rolling and watering before play.
Buildings with movable trays or modular turf systems shift the constraint back to machinery, which is predictable but expensive to maintain.
Markings and branding take longer than expected
Different sports require different line sets, sponsor positions and league marks, and painting or masking a field consumes crew hours after the surface is ready.
Digitally inserted graphics reduced some of this for broadcast, but the physical field still has to satisfy officials and players.
Where lines from another sport remain faintly visible, it is normally because the conversion window did not allow a full repaint.
Everything else changes too
Goal structures, benches, penalty areas, timing equipment and camera positions are all sport-specific and are stored, moved and installed each time.
Broadcast cabling routes differ, and the positions that work for one sport put cameras in the wrong place for another.
Even signage and wayfinding change, since the entrance a supporter uses depends on which configuration the seating is in.
Why the constraint is economic
Each conversion consumes a crew shift, and crew shifts are the recurring cost that decides whether a second event in a weekend is profitable.
Venues therefore group similar events together, running several of one configuration before switching rather than alternating.
That grouping is why a shared building's schedule looks clustered, and why the flexibility it was designed for gets used less often than the design assumed.

