Barring any single company from negotiating to buy more than a certain percentage of a given existing market of goods would be a start. Companies would still be free to build their own factories/fabs if they didn't like it.

That, and putting Sam Altman in jail for being a lying fraudster.

One or two companies will come out of this, designing and engineering memory and partnering with someone else to do the fab of that memory no different than making processor chips in Arizona.