Slightly overstated. Tiny teams aren't outcompeting because of AI, they're outcompeting because they aren't bogged down by decades of technical debt and bureaucracy. At Amazon, it will take you months of design, approvals, and implementation to ship a small feature. A one-man startup can just ship it. There is still a real question that has to be answered: how do you safely let your company ship AI-generated code at scale without causing catastrophic failures? Nobody has solved this yet.
I think there's a parallel here between people finding great success with coding agents vs. people swearing it's shit. But when prodded it turns out that some are working on good code bases while others work on shit code bases. It's probably the same with large corpos. Depending on the culture, you might get such convoluted processes and so much "assumed" internal knowledge that agents simply won't work ootb.