It’s mathematically proven that no voting system is perfect, so you’ll have to choose what you value most in a voting system. There is no clear best system.
I think the arguments for approval voting are strong. It’s simple and easy to understand, no need for complex multiple rounds of counting. Since you can’t rank candidates it doesn’t suffer from the spoiler effect.
In your hypothetical scenario you’re forgetting the Trump voters who will vote for Sanders again after they see Biden nearly beating him. RCV has a bigger problem which is called the spoiler effect where, without strategical voting a loser can influence the election results. And am I missing something or should the numbers in your RCV list add up to 100%?