First thing EU reported is that they want to reduce the dependency of Russian gas.
It is never going to be All or Nothing, where as energy is provided by companies that are listed in public Stock Exchange. This means they are not necessarily own 100% by Russian. I happen to own few stock of Gazprom :)
If EU would make total trade barrier over Russia, their economy would collapse into chaos in matter of weeks as the supplies of all kind would be reduced to none (Russia has almost every kind of natural resource, but would not be able to answer the sudden huge growth of demand, the adjusting would takes months, even years if the infrastructure is not adequate). Oil and energy can be bought from anywhere (mainly from OPEC countries), only the price would surge. This would hurt everyone.
Nobody wants to cause humanitarian chaos in Russia, but they could face very hard sanctions which would hinder economic growth. Also, the foreign capital is not going to flow in to Russia after these kinds of events, which has, is and will hinder their growth for couple of years to come.