Cooling a mini-itx board with a 14mm processor with <90W TDP is not a unsolved problem. But the standard ATX motherboard layout assumes most of the head will be generated by the processor, and that's simply not true today. A dual GPU setup for gaming or ML might generate 5 to 10 times the heat generated by the processor, and there's literally a couple centimeters for airflow between the two cards.
When I see an innovative design that maximizes airflow across the GPU(s), preferably one that involves removing the stock "windtunnel" cooler and replacing it with massive "tower" passive radiators and 3x 120mm temperature controlled case fans blowing cool air across them, then I'll be impressed. (note that this would require either a new motherboard design or using pci ribbon extenders)