A GIS analyst publishes a 3D scene from ArcGIS Pro to ArcGIS Enterprise to create...

Hosted 3D scene layers are stored in the tile cache data store, which is optimized for storing and serving cached 3D content, such as buildings and elevation surfaces. This data store supports scene layers published from ArcGIS Pro and allows for efficient rendering in 3D web scenes within the portal.

The relational data store is used for feature layers and structured tabular data. The raster data store supports large raster datasets for imagery layers. Neither is appropriate for 3D scene layer content. Thus, for hosted 3D scenes, the correct data store is the tile cache.

Reference Source: ArcGIS Enterprise Help — Data store types and publishing workflows