Unlike Russian soldiers, this boycott is not intended to kill civilians. The main goal is a peaceful boycott of Russian casinos to reduce the inflow of money to the Russian budget from taxes, which will reduce the support for the war.
This could be an effective approach but I guess even if we boycott the Russian gambling platforms, it still couldn't stop the war because aside from taxes from gambling, they still have lots of resources to support their current war. Innocent lives are already suffering from what is happening to their country but I believe that this too shall pass. The sad thing is, that this war could continuously take more lives.
Of course, the mere boycotting of Russian casinos will not stop this war. We can already see that Putin does not care much about the sanctions and boycotts that many countries and corporations have imposed on Russia. However, if the number of sanctions and boycotts increases, it will eventually come to the point that Putin will have to surrender and stop the war.
The boycotting of the gambling platforms owned by Russians may not stopped the war but can be a good move to show that Putin aggressive attack on innocent Ukrainian citizens is a wrong move. Putin needs to be sanctions heavily for breaking international humanitarian law by attacking civilians and residential areas . This war is supposed to be against Ukrainian soldiers not the citizens that know nothing about war how how to use wapons to fight. Putin has taken a wrong move against the innocent civilians.