There's been so much inflation that $3/gallon would be really cheap, even for gasoline in the US, by the standards of the last 20 years or so. A very arbitrary number to get stuck on.
US Average Gasoline Price Adjusted for Inflation
$4/gallon just isn't that high, not much out of line with the last ~15 years.
I think higher fuel prices could be the impetus for quite a lot of alternative energy, alternative transport, and electrification investment. I think if you believe that free markets work, you'd really have to agree.
Think of the conspiracy theories we got for the COVID vaccine. Now, think bigger.