If blood is essential to the body and its circulation makes the body and mind work, then oil does the same to the world's body and its functionality. There are other forms of energy that are being used but the direct and indirect usage of oil by any country and world is large and complex. And if looked at the supply side of it there are a handful of countries that provide it.
The complexity is much deeper but for the article purpose, this amount will be sufficient. For the mentioned reasons replacement of supply or removal of supply from one of the countries is like giving an electric shock to the body that may result in shutting it down.
EU and USA are going to discuss oil import ban from Russia to Europe. This is being thought of because the current sanctions have not resulted in Russia reducing the military operation or demands on the negotiating table. This will be an extreme and dangerous step to take as the replacement is the bigger issue.
There are two major options, one being Saudi Arabia which is unwilling to deviate from OPEC+ commitment and has recently faced an attack on its facility resulting in some supply issues. Another option is bringing back Iran oil through an agreement on JCPOA that is currently paused and required large steps from the USA.
The step and its impact along with no sight of a replacement will increase the probability of financial crisis and a global depression. It will also result in neutral nations finding ways to secure their energy requirements as it becomes a national concern leading them to take a side directly or indirectly.
Last thing the global economy needs is energy and food crisis along with already hampering stagflationary indications due to steps taken by few countries.