If Europe truly goes with energy embargo for years or decades, the only winners are the oil producers. Europe loses out at least as much as Russia if it chooses so. Russia simply sells to others and they will find a buyer for every molecule of oil they produce since everyone not only wants to buy oil, they need to.
By doing that Europe is only doing the US a big favor while it hurts itself and seemingly hurts Russia. Basically Russia is the shop selling products that everyone needs to survive and Europe is telling the shop owner it will not buy food but rather find whatever is on the ground or go to another store that sells for 1.5x the price. It only hurts Europe. The other producers are going to love this and the USA is a producer too.
Well it's good for Iran, Saudi Arabia, UAE and so on. Every other major player is rushing to secure energy. Either way it's imperialist powers going at each other. Ukraine stuck between two powers and abused.