Snowballing also happens a lot in SC2, and also even in Chess. That's simply the normal way to win, even if on the other side it feels bad when you get steamrolled by overwhelming forces.
Comebacks in high-level SC2 games don't usually happen as you say. More often, the losing party relies on their opponent overlooking some peculiar tactic like using DTs (for those who are not familiar with SC: invisible units that can only be detected with specific means). Otherwise a bad engagement very often means defeat in short/mid/long term.
Finally, ZK does have very long range static weapons that can hardly be countered (unless you destroy them). If the opponent "camps" in their base, you just start to build one that will either vaporize their army or buildings, or slowly wear them down. But really, camping is usually newbie-level strategy.
Comebacks in high-level SC2 games don't usually happen as you say. More often, the losing party relies on their opponent overlooking some peculiar tactic like using DTs (for those who are not familiar with SC: invisible units that can only be detected with specific means). Otherwise a bad engagement very often means defeat in short/mid/long term.
Finally, ZK does have very long range static weapons that can hardly be countered (unless you destroy them). If the opponent "camps" in their base, you just start to build one that will either vaporize their army or buildings, or slowly wear them down. But really, camping is usually newbie-level strategy.