An outdoor basketball court and a gymnasium floor look similar and are engineered for opposite problems. Almost every difference between them exists because one of them is rained on.
The surface is chosen for water, not for bounce
Outdoor courts are typically asphalt or concrete, sometimes finished with an acrylic coating or a modular tile system. All of these tolerate moisture and temperature swings that would destroy a hardwood floor.
The cost is grip and give. Hardwood on a sprung subfloor absorbs impact and returns energy; a concrete slab does neither, which players feel in their joints over time.
Coatings and tiles recover some of that and are the reason a refurbished park court plays noticeably better than bare asphalt.
Slope and drainage are designed in
An outdoor court is built with a slight pitch so water runs off rather than pooling, and the direction of that slope is chosen relative to the baskets to minimize its effect on play.
Drainage around the perimeter matters as much as the slab itself, because standing water at the edges undermines the base and produces the cracks that eventually end a court's life.
Indoor floors need none of this and instead need humidity control, which is an operating cost rather than a construction decision.
Rims and nets are built to survive
Outdoor rims are heavier, often fixed rather than breakaway, and mounted on posts engineered against wind and hanging. Nets are chain or heavy synthetic because standard nylon degrades in sunlight within a season.
Backboards are steel or fiberglass rather than glass, which changes the rebound noticeably. Players moving between the two surfaces adjust their shooting without necessarily noticing why.
Wind and light change the game itself
Shooting outdoors involves a variable that does not exist indoors, and it particularly affects longer attempts. Court orientation is chosen to keep low sun out of shooters' eyes where the site allows.
Lighting turns a court from a daylight facility into an evening one, which typically doubles its usable hours and is the most requested upgrade in most neighborhoods.
Maintenance expectations differ completely
A gym floor is cleaned daily and refinished on a schedule by staff who are already employed. An outdoor court is inspected when someone complains.
That asymmetry, more than any construction detail, is why outdoor courts deteriorate. Building one is a project; keeping one is a habit that requires an owner.

