The Ottawa Treaty attempted to get rid of them, but it’s essentially just a voluntary thing. Ukraine did sign up to it, but many of the world’s major military powers did not. Unfortunately Russia is among those that didn’t. Since Russia is mining the front anyway, there’s little benefit to Ukraine not doing so

There is a small silver lining here - or a less dark patch of the cloud, maybe - in that modern mines are designed to make themselves inert or self destruct after a few weeks or months