As a counterpoint, I would point to how far we have been able to scale classical computers (over almost a century of work). We have gotten to the point where we are pushing up against fairly fundamental limitations of the physics (speed of light, quantum effects, ETC).
Given enough time, we will (through incremental improvements) refine quantum computers towards their theoretical limits. We will likely see practical applications long before we reach these limitations.
Comments
As a counterpoint, I would point to how far we have been able to scale classical computers (over almost a century of work). We have gotten to the point where we are pushing up against fairly fundamental limitations of the physics (speed of light, quantum effects, ETC).
Given enough time, we will (through incremental improvements) refine quantum computers towards their theoretical limits. We will likely see practical applications long before we reach these limitations.