I have looked a several charts, and that is not an honest comparison. A derailleur will not be 1.5% energy loss across all gears. And I've not seen a chart for

I have looked a several charts, and that is not an honest comparison. A derailleur will not be 1.5% energy loss across all gears. And I've not seen a chart for an internal hub that had 15% energy loss across all gears. If you actually take a look at your derailleur system, you'll notice that a) the chain is not straight in all but a few settings, b) it has a somewhat complicated arm with an extra sprocket to keep the chain tight. And it is harder to protect it with a guard, so you end up with more dirt in the system if you use it every day. But yes, internal hubs are heavier, generally somewhat less efficient, and better protected against the elements.