Black and brown people at the bottom ever subservient to a small elite of rich white cis straight men. It was never about the ‘unfairness’ of affirmative action. If it was you’ll also see them taking aim at the unfairness of legacy admissions as well. It has always been about keeping black and brown folk down and maintaining hierarchy.
Hold on let me find Dorothy, Tinman, and the lion and we have the entire crew to hang out with strawman.
Ignoring the fact that AA has nothing to do with legacy admissions and frankly wouldn't survive a challenge on it's own even in a less stacked court; no I do not think banning legacy admissions would be effective policy. Legacy admissions allow an individual to expand capabilities and capacity of educational institutions and get a favor in return. At it's core it helps more individuals get education at the cost of unfairness which frankly is built in at every level. That rich person will always have an advantage. You've fixed a small and trivial piece. They still have the network and funding.
It's frankly hurting the intended recipients to right a wrong that will not be fixed unless you somehow eliminate income equality. It's bad policy in pursuit of an unrealistic standard for us to achieve in this decade+.
You keep mentioning whether it's effective policy, but that has nothing to do with SCOTUS. Their one and only concern is whether the policy is constitutional. Effectiveness is for the other branches of government to deal with.
Let's use a simple metaphor. You have a bridge. One side of the bridge is heavier than the other, so it's not balanced. You add a counterweight to balance the bridge.
Several years later, someone says "there's no need for this counterweight anymore, it's just unbalancing the bridge." If the bridge was rebuilt to address the imbalances, you'd be right. But it wasn't rebuilt, it's the same bridge with the same flaws it had when the counterweight was put in place. In an ideal world, we wouldn't need affirmative action. But pretending we're in that ideal world isn't actually solving anything.