So you think ARM should be spun-off rather than sold? It seems like Softbank is having some issues unrelated to ARM, and needs the money. I'm also not sure that Softbank ownership has contributed anything to ARM's success.
The issue is with the well-being of the tech ecosystem and less with SoftBank or ARM's well-being as a business. SoftBank may not have contributed to ARM's success, but their neutrality allows ARM to license their IP without the kind of self-dealing you would get if Nvidia owns it. Further, Nvidia has a poor track record in global citizenship.
The net result is that the overall ecosystem is going towards a degenerative state, rather than fostering innovation and diversity in tech.
