What you are saying makes no sense at all. I mean really none. If people have been marginalized by group for hundreds of years, then they require redress for that by demographic group. What you are saying is the moral equivalent of "well, all lives matter." It fails to take into account the specific injuries that have been done not to everyone, but to specific groups of people - and this has the net effect of silencing them and refusing to look at their particularly needs. (Which is the whole point of this narrative).
If the people who still hold the vast majority of social and political power (whites and white men in particular) would simply do more to provide those needed redresses, lobby groups would not have to form to demand it. This entire issue could be solved by listening to marginalized people the first time and not making them have to fight for what is only right. But, the apex of the dominance hierarchy doesn't want a flatter strata; they don't want to give up their privilege. That's the whole issue in a nutshell.
And your scheme does nothing to address the fact that white male identity politics still has huge sway - in both your country and mine. How do you propose to address that? Women advocating for the vote for 100 years is the only reason it was ever granted. The Civil Rights Act of 1964 came out of decades of advocacy - not out of the goodness of white hearts. Saying that this type of advocacy promotes the status quo is about the most delusional thing I've ever heard you say since advocacy is the ONLY thing that has ever lead to positive change.
I'm not sure if you've already read this or not but check out my story on how the BLM protests demonstrably lead to many, many concrete changes - both in laws and in other arenas. To ignore that this type of advocacy does lead to real change is to retreat into a fantasy land that is divorced from reality. You have no proof whatsoever that demographic advocacy creates little change and I have a huge amount of data, examples, and proof that it does. You're just telling yourself a fairy tale that feels right to you - but it's still just a fairy tale.