I think the idea that vehicles with emissions controls are inherently less reliable in any statistically meaningful way is highly suspect.
In addition, the most common failure points of vehicles are usually not related to the engine being unable to operate.
It’s usually accessory and wear issues: batteries, belts, tires, alternator, etc.
As a counterexample for you, the third generation Prius (2009-2014) has about the most bulletproof powertrain imaginable. Every UberX on the road is driving one with 300,000 miles on it and complete neglect-level maintenance.
eCVT transmissions in plug-in hybrid vehicles are simpler and more reliable with fewer wear parts (basically no wear parts) than pretty much every other transmission type, including manual transmissions.
I will also point out, being in the middle of nowhere should be ideal territory for electric vehicles if rural society had a little bit more imagination. They need minimal maintenance compared to any sort of combustion vehicle. You can avoid trucking gas and oil to remote locations, instead installing solar panels/batteries once (lord knows you’ve got plenty of land), set and forget it. Panels are dirt cheap and last 25+ years, batteries last 15+ years. Your oil deliveries are used once and depleted. Even without solar and battery, rural locations are far more likely to have electric utility service than any other utility.
300,000 is a joke compared to what most (non-hybrid) diesel engines last. Those are the ones that are most impacted by DPF and SCR systems that reduce reliability (in case of SCR, also DEF fluid you have to have accessible and add). Gasoline engines are not nearly as much impact by emissions controls IMO since as you say even the best case they normally not last past 300,000 (Toyota Tundra an exception that might even curb stomp the Prius, non-hybrid though) and emissions controls for those are more likely to last the life of the engine. It seems based on your comments that gasoline engines must be what you were familiar with but perhaps limited experience with [the usually more reliable] diesel engines.
The other bit about electric I see as a red herring. Obviously electric is superior if you have capacity and grid or battery for it, but it's a sideshow from emissions controls on outputs of petroleum engines. It's not an emission control on the output of the engine but rather displacing much of the work the engine is doing. It's still far from ideal for many rural/ag purposes. I've ran ag machinery in places where there isn't even roads let alone power panels or a place to hook in, either you haul diesel or you are fucked, and in fact it is often there so you can establish infrastructure in the first place.