After owning an Escape Hybrid (first gen) I'm convinced that arrangement of powertrain is the best for the real world. OK sure I do love rowing my own gears in a roadster with a high rev limit who doesn't? But for everything else the "Prius-style" eCVT is fantastic. Best of both worlds, gas-or-electric-or-both, very little to actually go wrong with it, minimum complexity. There's seriously almost nothing in there it's topologically a rear axle differential with the inputs and outputs flipped. No friction material to wear out. No dog clutches going in and out of mesh, no shift forks, none of that. Power delivery is seamless, hand-off between prime movers is seamless, torque management is seamless. We all have eyes, we can see the performance BEV's being marketed on their torque capabilities so I can think of no reason an upscaled eCVT would be unworkable. It would probably be necessary to do something nobody's done so far with a BEV or hybrid... include a frickin low range transfer case. Yes I know "bUt eLeCtRic HaS tHe tOrQuEs" ... sure it does but I don't know of any direct stator-to-wheel BEV's, gears are how you get more operating range from a given powertrain and while eCVT's have effectively infinite ratios they do still have a fixed maximum torque capability and ranged gearboxes are the proven way to fix that.
On a vehicle with eCVT there aren't really 2 powertrains there's the gas engine and there's a transmission that can also store energy. The transmission has fewer moving parts than any manual or automatic conventional transmission and zero wear parts, clutches or anything that is taken into or out of mesh. The transmission happens to include two electric motors but they're all just part of the same housing and not exotic or fragile. The motors can move the vehicle with the engine powered off and the engine can move the vehicle with a flat battery by using the series output motor as a generator to retard the parallel motor. They also can eliminate complexity elsewhere because you don't need a starter motor, you don't need a turbo to get driveability out of a low powered motor, and you can run the gas engine within an optimal range of speeds so it doesn't need VVT or variable geometry intake manifolds or other BSFC-widening trickery.
Some hybrids have an extra powertrain for example toyota highlander hybrid has no driveshaft from front to back and the rear power unit is its own independent drivetrain. I am less inclined to like that both because it's redundant complexity and also it means the rear drive unit has a very limited amount of power so if you have plenty of traction on the rear, none on the front, and you need a lot of power to get moving you're out of luck. I think it's some comically low amount of power too like 15 horsepower. The first gen Escape PHEV had a more typical auto-4wd arrangement with a single unified hybrid powerplant; engine and motor power were equally available to front and rear drive axles by conventional PTU and driveshaft.
The diesel option puts out even more torque. 
