Answering that specific question, 98 jumped up 16% this spring and... that's it. Except for that, it's an ordinary curve compared to, say, 5 years ago. And that's mostly the result of actually bombing the refineries.
And yes, if US and EU were serious about helping Ukraine win, this would have already happened back in 2022. Or better yet, back in 2014.
As it is, US & EU sanctions seem to be more of a theater mostly for the benefit of the population of those countries, so that their politicians can sincerely say that they "support Ukraine".
Depends on the claim - some are, some aren't. The problem obviously exists, but the coverup is good enough to make lots of people think that the war happens on another planet and doesn't affect them (e.g. gasoline export ban).
"In breaking news, Russia is extending the complete ban on all petrol exports through the rest of 2025 for producers and distributors, and is banning diesel exports for distributors.
Fuel shortages have spread to almost all of Russia, with the Ministry of Energy insisting that “all necessary measures are being taken to ensure the timely and uninterrupted supply of all essential fuel.”"
So they stories no fuel in Russia are just propaganda?