Well, the tyranny is here, it's obvious now. The question is, what are people going to do about it. Will they let themselves become total slaves, or will they resist?
Tyranny always bring misery, otherwise it wouldn't be a tyranny. Therefore it is not the question “will the people resist?”, but “when?”. Historically, when prices of food gets over 40% of income, revolutions start. Keep an eye on statistics.
There has to be another metric. I don't think this one is reliable anymore. The price of food is already cheap and they will just lower the quality of it to lower it's price with cancer causing GMO and pesticide.
The food price in the modern economy is not an issue anymore. So if this is your metric, then tyranny will stay forever.
And I am not even sure a revolution is beneficiary, you will probably get a military dictatorship after that, and the people will lose even the few rights they have now.