Within the constraints of a small-government capitalist worldview, I don't know if you can.
In that worldview, General Mills has a right to sell desserts for breakfast without government interference, parents have a right to feed that to their kids without government interference, and kids have a right to enjoy them without government interference.
That a generation later, a homemade breakfast feels like a weekend project that ought to be made special with all sorts of elaborate dressings is apparently just something to be accepted when these rights are honored.
I have no idea how you "outcompete" Captain Crunch with a bowl of rice porridge in that world, and can only imagine the outcry and lawsuits from General Mills if the government put much meaningful effort into trying.