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.
Well if the the sanctions which have been imposed by the US and their allies have not been enough to stop Putin from invading Ukraine it was unlikely a small boycott was going to have too much of an impact, but despite all of this if people want to vote with their wallet and not support any casino which has any kind of relationship with Russia then they are on their right to do so.
I think this is more of a personal choice based on individuals on what they think about this boycotting of a thing. No body ever supported the invasion of Russian soldiers on Ukraine by based on the directive of Putin. There had been many sanctions on Russia but it looks like the sanctions is not having any effects on Russia based of the muscles of the Putin and the Russian soldiers. Taking this into action is good but it all depends on every individuals.