You do, if you want to know what wattage you're using. Wattage is a much more meaningful unit that carries across to other atty's in a more comprehensive and understandable manner. I'm not against your idea of keeping VV, but I am one of those people who has moved on to VW and never looked back. I'm all for giving people options though.
ProVape's market is not the technically inclined, other than those of us who appreciate the over-engineering that goes into their designs. They're the "Apple" of the vape market - built right, and easy to use.
That's where we get into Joules, and that's a different brand.

Nobody needs to be concerned about current or voltage when wattage is the result that's much easier to comprehend. Wattage is also a "result" not an "electrical component", which is why it's easier to comprehend. Nothing adjusts wattage - there is no such thing;
everything is variable voltage. The wattage setting is being decoded by a chip and the circuit is still adjusting voltage.
You just took the words out of my mouth, and proved why VW is superior. "
Providing that the atty's resistance is stable" - it's NOT, which is the point of VW. Kanthal (or any other wire) changes resistance as it heats up - that's the science behind temperature control/limiting, and why nickel wire was chosen - it has the greatest resistance change from cool to hot. VW devices constantly measure the resistance and adjust voltage on-the-fly to keep the vape consistent. Also, as the coil ages, the resistance changes.