The begining of the end of the Prius - Time

I agree with the flavor of much of what you said. With the caveat that just because a BEV doesn't work for your needs, doesn't mean it won't work for a significant fraction of the market.

As for the quoted text though...
I agree that the efficiency improvements are more significant, but only from an engineering viewpoint.
From a viewpoint of customers in the larger marketplace, efficiency gains, especially right now, mean little.

I expect the increase in handling to do more to increase sales than the increase in efficiency.

 

Low maintenance costs are a big reason for the popularity of the Prius and Camry hybrid in Australian taxi fleets. The ubiquitous Ford Falcon is much cheaper to buy, bigger interior, available with factory LPG injection for half-price fuel. But over 500,000km the total cost of ownership is well in favour of a "complicated" hybrid.

As for hybrid sales in Japan, they have all but eliminated the V8 from about 2014. The only exceptions appear to be the Lexus LS (V8) and IS-F (V10) and the Toyota Century (V12). The standard VIP car in Japan had a 4-5L V8. Now they are 2.5-3.5L V6 with a hybrid system, delivering similar power and much better economy under the JC08 test. For example, the Mitsubishi Dignity has a 3.7l V6 (225kW) with hybrid system (50kW). The Toyota Crown Majesta, which was a 4.5L V8, now boasts a 215kW 2.4L V6 and 147kW hybrid motor (Note: I'm not sure of the nominal output of those motors or the total system power. And I don't have figures since MY 2014.)
Even Honda, Nissan and Mazda have mild-hybrids.
Even hybrid trucks appear to be quite popular.
And hybrid cars make for easy 4WD versions without heavy and complex transmissions.
No pick-ups, however.

 

And another thing, the standard for European PHEV AER appears to be 50km (30 miles) as a balance of useful range with reasonable domestic charging time.The two plug-ins still available in Australia (Outlander PHEV and Audi A3 e-tron) have 50km. (The PiP was never sold here.)
Since standard voltage in Japan is 100V and USA is 120V compared to 230V in Europe, I wonder if the domestic charging time was a bigger consideration with the PiP and Prime in their key markets compared to Golf, Audi, etc. in theirs.
The outlier is the Outlander PHEV (built in Japan, popular in Europe), but it has adapted iMiEV tech and therefore started with a bigger range.

 

Mazda is licensing from Toyota, so their hybrids are HSD derived.
Honda hybrids are now full hybrid, and that may be true of Nissan's.