Even Nvidia's gains are based on selling that hardware to outlets buying GPUs in shipping container quantities to run huge LLMs. If those companies dry up, so will Nvidia's market position. At the other side of things, their traditional market is gaming, but that industry is contracting and may not be making games that push hardware limits the way it used to. Their best long term bet might be a rumored Steam Deck/Switch like handheld (one of their own making; they do supply the chips for the Switch and upcoming Switch 2), but that's not going to justify a $3T market cap.