Russia's actions have shown that it is not a reliable partner, and the "cheap" energy it sells actually comes with a very high political and national security cost. As a result, most European countries now know that they must realign their energy policies and economic relationships.
This kind of re-alignment takes time. By opening up the strategic reserve, Biden has given Europe more time than they otherwise would have had. Hopefully, it will be enough.
Western Europe has known this for decades and did not care. Germany used the past decade to decommision nuclear power and coal power. This was not a mistake and US taxpayer oil reserves should not be used to bail them out because they knew what they were doing.
Although it does benefit Europe, it also benefits the United States for Europe to finally turn away from Russia. Germany's prior willingness to engage with Russia may have been purposeful on Germany's part, but it was against the interests of the United States. The United States is not "bailing them out", but is instead making it economically possible for Europeans to align themselves with our own national security interests.
The alternative is for Europe to abandon the fight in Ukraine. This is something that the US taxpayer should be willing to pay to avoid.
This kind of re-alignment takes time. By opening up the strategic reserve, Biden has given Europe more time than they otherwise would have had. Hopefully, it will be enough.