The point of sanctions is to make people like these Yandex employees discontented. Before they could shrug their shoulders, going along with it because there was little choice, and live their lives in stability and comfort, sheltered from the atrocities perpetrated by their government. But now they are harmed through economic retaliation. Ideally it drives down Russian support for the war and Putin's popularity, which right now are disgustingly high.

Maybe it works, maybe it doesn't, it's drastic and heavily coercive, and it's arguably collateral damage. But it's not like these Russian programmers are having their apartments shelled. This is war through other means, and war is hell.