I quit smoking using a vape and then quit vaping.
I found that it was easier to quit smoking using a vape because I kept the same motion. I needed a powerful one to feel a similar hit.
And I found it easier to stop vaping than to stop smoking because I could mix liquids to have any desired nicotine content, allowing me to reduce it very gradually. A lot of people simply replace smoking with vaping but that’s still an improvement.
There is no best way. What matters is what works and different methods work differently on different people. It’s good to have a multitude of ways.
As for efficiency it seems that vaping is very efficient.