Only because those countries choose for that to be the case. For example, Saudi Arabia and Russia don't do that. Local prices and export prices are different.
But the US, Canada, the Netherlands, and long list of other countries could make this crisis have zero effect on local prices. They choose to take every excuse to raise prices (in fact the Netherlands goes further: if sales tax on gas raises because prices raise, the amount of tax paid is kept constant if prices drop. So they artificially raise local gas prices. So if gas prices are low, tax on gas has at one point reached 72%), but it is fundamentally a government choice.
