So you lug around all that dead weight just to be able to provide you with enough power for takeoff that you don't use after that.
So you argue that instead it's worthwhile to lug around an extra electric engine plus a significant amount of batteries for the duration of the flight, just to get a little oomph during take-off?
Don't get me wrong. IF we can get energy storage (batteries) sorted and IF we can get the grid updated so that it is able to deliver the power required to charge our batteries relatively quickly, I think 100% electric is the future. First for cars, later on for aircraft.
But hybrid aircraft, sort of like a Cessna Prius? I don't think so, particularly not if the electric bit has to be charged at some point from the fossil fuel bit of the aircraft somehow. Aircraft normally don't brake (so no regenerative braking possible) and they don't crawl along in traffic jams or city traffic - the places where hybrid cars can achieve the most fuel savings.
A hybrid car on a constant highway speed uses almost exactly the same amount of fuel as a normal non-hybrid car. And that scenario is by far the best comparison to an aircraft in flight. Minus one thing: The weight penalty for aircraft is much higher than for cars. So carrying around all these batteries will have more impact on energy required in airplanes than in cars.