AMD has the one thing every NVIDIA challenger needs and almost none of them have: a track record of taking market share from a dominant incumbent, which it did to Intel in server CPUs over the previous decade.
Instinct accelerators compete credibly on memory capacity and bandwidth, which matters enormously for inference on large models. The gap has always been software, and ROCm is the long bet: an open stack that customers can fork rather than a proprietary one they must rent.
AMD is also unusually straight with its numbers. It quotes both dense and sparse throughput, which makes its figures less flattering and more useful than a headline that only gives you the larger one.