I think this is a perfect summary. No system is perfect but at least the flaws are consistent and well-known, not subject to the whims of a particular group on a particular day.
>> opaque rules has an advantage in that it's more difficult to game the system
You are right that with opaque rules, you cannot study your way into college anymore -- because it will depend on who you know, which charitable boards your parents are part of, which civic organizations you support, how good your sports videos are choreographed, how good an essay writer you hire for your college application, how genuine your weekend "service trip to country x" photos look, etc. When you get rid of tests and replace them with opaque measures that is the sort of gaming you end up with -- and that seems like a far worse type of gaming.
I'm comfortably middle class, studying way into a good college from below poverty. Prep books on weekends for 2yrs. I realize it is hard, it isn't fair -- but I dont want to replace that system where my children have to buy their way into college -- which is where we'll end up. I'm not wealthy enough to donate a building. I'm not connected enough to land on a charitable board with a college administrator. My kids have to study their way in.
Now...i'm hearing there is no way to study their way in. Rather, we need to figure out how to please each individual school's decision makers. Is that really what is more fair? Is that what the 99% want?
I think you've hit on a key point which raises the obvious question: Who benefits?
Dismissing standardized testing reduces people who do well at tests, either through skill, speed, or rigorous study.
What groups, experiences, or attributes does it select for?