People are sanctioned, people are unhappy, people protest their government that allowed it to happen. It’s how you put pressure on the leadership of a country.

This doesn't follow. First of all, no change happens internally in the USA despite its own citizens complaining of material conditions; so to say that people being unhappy and protesting necessarily leads to change is false. Second, every other sentence people say about Russia is calling it "authoritarian", "dictatorship", etc: you can't simultaneously pretend its an authoritarian dictatorship and also that the people protesting have any say in its trajectory.

You can’t force Russia’s hand in this, but you can make the situation for their people uncomfortable.

Which is just wrong. You're making the everyday civilian uncomfortable. You aren't doing anything against those who actually make decisions. Instead you're punishing someone for their nationality, or where they were born or choose to live. It's punishment for something they didn't do and it's not constructive.

The alternative would be to say “Russia pls open the grain corridor again” and I think you can imagine their response.

Sure, I understand that you're saying Russia isn't going to just cooperate with requests. But it's also not going to be any more likely to cooperate because you've made the lives of their citizens, or people of Russian ethnicity living on foreign soil, any harder.

In the end this just punishes innocent people and does nothing to achieve the stated goal.

Those polls you got your source from are actually polls done by state-run polling facilities. of course poeple are going to say what the state wants to hear. here's a video on it. https://www.youtube.com/watch?v=_uQCNjIHeqU

Btw, by saying that "80% of Russians support this war", you're spreading Russian state propaganda.

And of course protests in Russia died down, people get jailed for like 10-15 years in prison if they protest, so by fear of getting jailed, protestors stop. it isn't pretty but it's how the system works.