

Russia will continue fighting as long as they can and Putin is in charge. The only two ways to end the war are to break the Russian ability to attack, or to get rid of Putin. The former is significantly easier than the latter (though it might lead to the latter).
So the EU kicking all Russians out of Ukraine would de-escalate and end the war. Not doing anything means Russia will continue its attacks and find new ways to do even more damage.
Sounds interesting, but considering how thick hydroelectric dams need to be to hold back a mere lake, how thick are these spheres going to be to hold back an entire ocean?