On the flip side, without the government to enforce a contract one party has broken, there would be no reason to ever fulfill a contract - you'd have to rely on citizen's force, and history has not shown that it's been particularly good to rely on regular citizens.
Betting on government inaction for breaking the law is still using the government. If it is illegal, then a competing grocery store should be able to open its doors and any lawsuits thrown out. Considering Albertsons’ and other grocery store’s lawyers are not willing to bet on this, it must be clearly illegal, which is again, a problem the government has to solve.
a competing company could open a store there anyway and then fight the battle in court; they might even win, but the cost of the court case would prevent most companies from even trying, after all groceries are a relatively low margin business--if this were a gold mine instead of grocery store you can be sure someone would have opened it already and fought it in court
Any contract that intends to reduce the amount of buyers or sellers could be made unenforceable.
This is clearly illegal, the fact that nothing has been done about it yet says nothing about it being legal or illegal. Just because a crime has been going on for years or is difficult to prove in court does not mean it is not a crime. As we type there are multiple monopolies that are illegal and could be tried in court but aren't. Those companies are not "using" the government to get away with it, they are using their money and influence to escape consequences for as long as possible. Again, call it what it is. A crime.