Plain hybrids currently do sell better than PHEVs or EVs.
I'm not sure in which "best of both worlds" a standard hybrid is better than a PHEV - a PHEV allows for cheaper fuel (grid electricity) when it's available. That being said, the extra cost is associated with larger batteries than standard hybrids. As batteries come down in price / size, I'm not sure why people would want a standard hybrid over a PHEV.
I'm not sure in which "best of both worlds" a standard hybrid is better than a PHEV - a PHEV allows for cheaper fuel (grid electricity) when it's available. That being said, the extra cost is associated with larger batteries than standard hybrids. As batteries come down in price / size, I'm not sure why people would want a standard hybrid over a PHEV.