Well, they tried to legally prohibit it, but as people in that thread pointed out, it's legally irrelevant in most developed countries ... so another hardware maker can fund a (legally) independent team in say France (most favorable reverse engineering laws) to break it / copy it / do whatever they like ... and then open source the output for the rest of the world.

It's even dubiously legal in the US ... but there it would be a war of legal fund attrition and Nvidia has deep pockets.

Still - break it in France, give it away ... US laws go poof.

It's really just the ongoing development of the software ecosystem that gives them their moat ... but it's a good technical moat because they steer future dev and others play catch up.