Fully agree with your thoughts! Except that the cost of electricity here is cheap enough that even if we plugged in every day, there is still a significant cost savings compared to Petrol cost per km.
One just has to consider your trip pattern and range requirements. My last road trip was from Adelaide to Coober Pedy. One stretch was 590km of roads with no towns in between. It would have been impossible to make that leg with a pure BEV !
Thankfully MG here offers a 7 year warranty , and fixed price servicing.
For the odd longer trips, the PHEV works out just great because it removes the need to charge when the infrastructure is really poor.
But PHEV's are not proven to be economical on longer, repeated frequent trips.
You get about 50 miles of EV range, then after that, you are hauling around all that extra weight of a exhausted battery pack, which eat's into the MPG figures.
There will always be a place ( for now anyway ) for PHEV's in certain usage cases, or until EV's have enough range or the charging infrastructure improves massively.
But, remember that NOT all serviceable items are covered by the cost of a service plan !.
E.G :- With the VAG group, brake fluid changes and A/C service costs are NOT included in the price of a standard service plan !.
Brake friction pad wear, transmission fluid replacement and a cam belt replacements are ALL not included and are chargeable as extras to the customer.
This is just to name a few.
Ask me how I know this !.
I would imagine that MG is NO exception to this rule.
You will see your service costs rise almost every year that you submit the cars.
These costs have to be absorbed by the customer. in order to retain the warranty validated.