Nodes are important, but I do hope that you understand that it needs to be a trade off. Since what would be the point of running a full node if we do not even use the blockchain directly ourselves since we would need to rely on third parties since transacting on the main Bitcoin blockchain would become prohibitively expensive. How many people do you think would run these nodes for the banks, payment processors and like you say a few billionaires? I would argue that the opposite is true, if more people are using Bitcoin directly the more likely it will be that we will have more nodes. Arbitrarily restricting the amount of people that can use Bitcoin directly would therefore not lead to an increase in the amount of nodes. Furthermore in terms of access to governance nodes are not as important in terms of governance compared to the miners, and miners do not even run full nodes, that is why miners would not be effected by this change whatsoever.