The California system, and other proposals I've seen, take district map making away from party biased state legislatures and give it to ... party influenced 'independent' commissions. A common formula gives 'both' parties equal say in appointing members of the redistricting commission. The big problem I have with this is that the two parties don't represent everyone. There are other parties. There are a growing number of people who associate with neither party. Giving up control of our government to these two squabbling groups, and codifying it in law and amendment to state constitutions, seems like a bad plan to me.
The California plan makes a party of 5 Democrats, 5 Republicans and 4 independents. A recent proposal for Illinois suggests 3, 3 and 1. These proportions are right for no particular reason, and sooner or later, perhaps immediately, they will be wrong.
What's the alternative? We could hold special elections in November of Census years to elect the map makers for the next year. If this is done right it would elect people representative of the population. But, it wouldn't do anything more than that. I can't think of any process that will give us sufficiently enlightened people that will reliably draw maps that actually represent 'communities of interest'. I hope someone thinks of one. Until then it's just more government by dysfunctional duopoly.