Sure it is. Lower efficiency means you need more panels, larger panels, and more support infrastructure. It limits where it can be deployed and makes it less competitive.
The cost is what makes the decision for deployment, not the efficiency. Perhaps this efficiency makes 2-axis tracking economical enough to justify, and then it gets deployed, but in the end the efficiency wasn't as important as the improved costs.
There are vast chunks of empty land in AZ, NV, NM, TX, CA that could easily fit enough solar panels (each) to power all of the US. The issue is cost of panels and no base load supply.