At Ancient Olympia, the birthplace of the Olympic Games, humanoid robots kicked soccer balls, boxed and even attempted archery — but also froze mid-routine for battery swaps.

The spectacle at a four-day conference and display event underscored both the promise and the hurdles facing humanoid machines, which lag behind the rapid progress of artificial intelligence.

Experts say limited real-world training data slows development, though collaborations among researchers, data firms and manufacturers are drawing billions in funding.

Developers showcased prosthetic hands, brain-cell-powered chips and other advances, offering an fresh look at a field still wobbling but steadily marching toward practical use