The real "fun" with 4090s will start in 2-3 years when cards will be dying outside their warranty period.
AMD's mistake, very noobish, but at least didn't reach sales. And even if it did, that 8pin connector might, don't know, be handling power nicely even half inserted. The problem would be with connectors not secured correctly, to dropping out of the card socket (all that vibration from fans could make it happen) and people having a non functional system. Best case scenario, they put the cable back on the card. Bad scenario. They don't have technical knowledge and they call a technician meaning expenses to pay that technician or staying without a PC until a technician in the store they bought their PC fixes the problem. Worst scenario. Technicians convincing them that the card is dead, isn't covered by warranty and they need to buy a new one. The technician gets a free GPU, AMD loses a customer and people paying a graphics card twice.