Yeah, there are a number of folks looking at this from the military side I’ve seen saying that they believe it to be better to be defending rather than attacking. Generally, a defender has the advantage, and Ukraine has pretty well-fortified stuff in the area, so they can leverage that advantage.
The Kursk offensive is embarrassing to Russia, but as far as I know, it doesn’t have strategic implications. Russia capturing Pokrovsk would make defending some other areas in Ukraine difficult.
That being said, there are a lot of aspects to the conflict, so…shrugs