I looked into this a bit. The answer might not be what you expected.
Domes are strong for a couple of reasons:
Compressive Strength: The dome’s arch-like structures, which we can think of as lines of longitude (called “meridians”), direct force down through strong materials that resist compression, like stone or brick.
Tensile Strength: When weight pushes down on the dome, it tries to spread out flat. The horizontal layers (like circles of latitude, or “hoops”) are being stretched and pushed outward. If these hoops are reinforced, as with steel cables, they prevent the flattening.
In classical architecture, domes mostly relied on compressive strength, with features like arches and extra supports (buttressing) to handle the load.
Modern domes use a mix of both compressive and tensile strength.
These puzzle domes rely entirely on tensile strength, since they don’t have arch structures. The interlocking pieces are like reinforced hoops, experiencing tension and resisting being pulled apart. This is easy to see if you watch it in action.