I know, it's a disgrace - apparently here in UK a lot of people buy PHEVs because they have a much much lower tax rate for company buyers, but obviously you get the tax discount whether you plug it in or not. So some people just....don't. Which as you said, actually means poorer fuel economy and increased complexity for zero reason. I absolutely think that those people should lose their tax discounts entirely.

I think that mainly happens when they are bought for fleets where cars are issued to drivers who did not choose the PHEV. The drivers are often told that they can be reimbursed for fuel and only need to turn in receipts, but there is no provision for reimbursement of electricity. This pushes people to just drive them as hybrids instead of EVs.

I’ve got to think that anyone who chooses and buys their own PHEV has done so because it meets their needs and they plan to use the EV mode significantly. Most PHEV drivers that I know hate it when they have to switch to gasoline partially because of the added noise and cost and partially because it seems like a kind of failure.

LPG is becoming progressively less common in Australia, this article[1] focuses on Queensland but the story is the same across Australia

”Since July 2010 there has been a 70% drop in the volume of LPG sales,” Mr Jeffreys said.

“The number of LPG registered vehicles has also fallen in the last five years.”

RACQ Technical Advisor Bill Reeves said the availability of LPG is set to further decrease.

“New fuel outlets simply aren’t putting in LPG bowsers and many existing stations are removing their LPG tanks when they are due to be recertified because the limited returns from the sale of LPG do not justify the expense,” Mr Reeves said.

Regional Queenslanders bear the brunt of the shortage with only one LPG bowser in 15 regional centres and no bowsers in Blackwater, Childers, Moranbah, Proserpine, Tully and Cunnamulla.

For residents of Moranbah this means a more than 270km round trip to the nearest LPG bowser at Puma Carmilla.

“Remote service stations may be less reliable because, if the LPG machinery breaks down, they have to wait a long time for parts and a technician to repair the equipment,” Mr Reeves said.

“This can cause problems for regional Queenslanders when there’s only one LPG bowser in the area.”

In addition to the shortage, no new LPG passenger cars are being manufactured in Australia and the benefits of choosing LPG are diminishing.

“LPG tanks in your car are expensive and must be recertified every 10 years,” Mr Reeves said.

“The costs associated with maintaining your car’s fuel tank means LPG is no longer a cheap fuel source for Queenslanders.

1. https://www.racq.com.au/Living/Articles/Wheres-the-LPG

I mean, that's a fair point, except that the pricing structure doesn't reflect the differences at all. Servicing a fully electric car should be cheaper, but in practice it just isn't. Servicing a PHEV should be more expensive but it also just isn't. A service of the E-Tron or the MB EQC costs the same as an equivalent ICE car even though there's hardly anything to do, and the service of my PHEV Volvo costs the same as the service of a regular ICE Volvo despite there being more to do.

So you might find that you'll get a fully electric Jeep but your servicing costs won't go down at all, it will still require an annual service to keep the warranty, and the dealer will almost certainly charge the same as for a normal one if not more(and I've seen dealers charge more, since EV cars can only be worked on by technicians trained to work on them, and there's comparatively fewer of them)