I keep saying that this idea of PHEVs being transitional is wrong and it should be easy to understand why.
A BEV that meets essentially all of your needs in terms of range has to have a battery ten times the size (give or take) of a PHEV that runs on electricity for 80-90% of your travel.
No matter how good batteries get, ten times will always be ten times - the expense, the environmental impact, the weight, the charging time.
Think about ICE cars - at least in the US, people want tons of power that they rarely use - you can get a car with 300 hp, but most of the time you're not using 30 hp.
It is never going to be optimal to have a battery enough for all your travel any more than an ICE for the maximum performance you might want.
The rational transportation device of the future has a small battery, a small ICE, and a big electric motor.
But the point I am going to keep making until I hear a good counterargument is that this is independent of foreseeable technology advances in batteries. It doesn't matter how you get your kWh or what it costs, it's not good for anyone or anything to utilize ten times the amount.