you seem to be comparing energy units with power units. 1 GW of installed solar capacity should be give about 1 TW hour of energy per year (365 days * 3 hrs per day as a conservative estimate).
I don't think they're confusing anything. If we use your numbers, then 180GW of solar is less than 5% of energy needs, and that is increasing at less than half a percent annually.
At that rate, decarbonizing by replacing a meaningful amount of the other 95% with solar will not happen in our lifetimes.