I agree. While I understand the practicality of Docker and facilitating development using it, I wouldn't call it "forward" progress.
The fundamental problem, as you say, is that our dependency ecosystems don't meet our requirements. Docker is one way to avoid the problem without fixing it since it's easier. Forward progress would be to fix the problem.
On one hand, Docker removes some pressure to fix the problem and encourages perpetuating it. On the other hand, maybe it gets people to think about the problem more. I don't know which influence is stronger.
The fundamental problem, as you say, is that our dependency ecosystems don't meet our requirements. Docker is one way to avoid the problem without fixing it since it's easier. Forward progress would be to fix the problem.
On one hand, Docker removes some pressure to fix the problem and encourages perpetuating it. On the other hand, maybe it gets people to think about the problem more. I don't know which influence is stronger.