A similar sentiment existed for a long time about Uber and now they're very profitable and own their market. It was worth the burn to capture the market. Who says OpenAI can't roll over to profitable at a stable scale? Conquer the market, hike the price to $29.95 (family account, no ads; $19.95 individual account with ads; etc etc). To say nothing of how they can branch out in terms of being the interaction point that replaces the search box. The advertising value of owning the land that OpenAI is taking is well over $100 billion in annual revenue. Amazon's retail business is terrible, their ad business is fantastic. As OpenAI bolts on an ad product their margin potential will skyrocket and the cost side will be modest in comparison.
Over the coming years it won't be possible to stay a mere 6-12 months behind as the costs to build and maintain the AI super-infrastructure keeps climbing. It'll become a guaranteed implosion scenario. Winning will provide the ongoing immense resources needed to keep pushing up the hill forever. Everybody else - except a few - will fall away. The same outcome took place in search. Anybody spot Lycos, Excite, Hotbot, AltaVista around? It costs an enormous amount of money to try to keep up with Google (Bing, Baidu, Yandex) in search and scale it. This will be an even more brutal example of that, as the costs are even higher to scale.
The only way Mistral survives is if they're heavily subsidized directly by European states.