Anyone who's been paying attention should know by now that the vast majority of hybrids on the market are pure marketing/greenwashing hype. They got a big early boost from the first hybrids to market, the original Prius and Insight, but very little since has lived up to the promise of those first two. If you look closely at those two cars, you'll quickly realize why -- they were designed from the ground up for fuel efficiency, and their hybrid motors were only a part of that strategy. The original Insight, for example, has a body made entirely from aluminum, with a minimized frontal area and vanishingly low coefficient of drag. In spite of its heavy battery pack, the Insight managed to be lighter than any other US-market car at the time. Its engine was a purpose-built, low-displacement 3-cylinder engine made with as much aluminum, magnesium and plastic as the designers could get away with. The electric motor was integrated into the flywheel, minimizing the extra weight of the hybrid system by allowing it to perform two functions simultaneously. The hybrid system helps, but the vast majority of the first-gen Insight's fuel efficiency comes from these things. Tuners have pulled the whole drivetrain out and replaced it with a 200-horsepower Civic Si engine, and still managed almost 50 miles per gallon out of the chassis!
From the above, it's pretty clear that hybrid drivetrains are just a piece of the fuel-efficiency puzzle -- yet ever since those first two cars hit the market, manufacturers have been tacking electric motors to otherwise ordinary cars and selling them to gullible consumers as the saviors of Earth. The electric motors are a little more efficient at low speeds, but everywhere else they're just additional dead weight that the gas engine has to drag around. Is it any surprise that these half-baked hybrids don't perform as advertised?