A small number of organisations control the models, the chips and the data centres that everything else is built on. That is a structural fact with consequences for competition, for who gets to set norms, and for what happens when one of them changes its terms.
Technical view
Concentration exists at several layers: chip design and fabrication, cloud infrastructure, frontier model development and application distribution, with substantial vertical integration and cross-investment between them. Competition authorities have examined partnership structures and exclusive arrangements. Countervailing forces include open-weight releases, falling costs and specialised smaller models, though the frontier itself remains capital-constrained in a way that limits entrants.
Related
Part of AI Terminology Index, section: Society and Impact.