To meet the $49 per gallon tax hike recommended by the U.N., fuel taxes in France would have to go up 17-fold.
As the note in Reddit stated, for 20 years they've been exhorted to go diesel by the same government that has now decided to make that prohibitively expensive. If you happen to live in a city and can get everything you need by bicycle, it's somebody else's problem, at least until your grocery stores' shelves start to empty as they have in Venezuela. At that point the damage is done. It isn't simply a matter of farmers raising the price on grain to cover the expense, it's a matter of them not being able to grow any.
The same is true of immigration. Even a brief glimpse reveals that those newcomers aren't farmers, plumbers, electrical linemen, or anyone who might actually supplement or supplant the working classes. They're mouths to be fed. They aren't net contributors to social services, they're net consumers, and the people who will have to feed them are being choked out of their ability to do so.
So this isn't about a 25 cent a gallon tax hike any more than the American War of Independence was about tea. It's about a mania for transforming society that has gone too far and has entrenched itself in the highest seats of power. Macron is only one of many.