Carbs: Less sensitive to fuel contamination.
Is that really the reason most planes still use carbs? I have never heard of fuel purity being an issue. Cars have had FI for many years. I fly a FI plane and would never ever buy one with a carb. I thought that carbs, with their lethal carb ice issues, are still used only due to tradition / certification inertia.
Re electrics, as stated, the motor is not an issue. I have worked with model plane brushless motors and some bigger ones and 250HP is easy to achieve with a unit weighing perhaps 30kg i.e. ~ 1/10 of an IO-540 engine. The batteries are the problem...
But even if suitable batteries are developed, you have to charge them from somewhere. We don't have the infrastructure to charge them in cars, and are not likely to have for many decades, which is why all mainstream-usage electric cars will be hybrids, perhaps with a small turbine to charge the battery. The power would all have to come from power stations and there won't be anywhere near enough of those about, for the foreseeable future.
Airfields will never get the infractructure to support electric planes - who would pay for it? Most can barely afford to fill potholes in the runway...
1. No carb ice.
2. No need for complicated constant speed props (as electrical motors have linear power output and no sweet spot).
3. No TBO - only limited by bearing life.
4. No CO poisoning.
5. No shock cooling.
6. No rich cut.
7. No degradation at altitude, no need for turbos etc.
8. Built in Fadec (brushless motors you set a RPM setting and it keeps it through the controller, no matter what).
9. No need to check oil.
10. Much less weight - 15Kw (21hp) R/C brushless weighs less than 2kg. That means that a O-200 replacement would weigh about 10kg. That leaves a lot of weight for a battery..
11. No dirt.
12. No vibrations.
13. No noise.
14. No leaning at altitude.
A lot of the above are actually non-issues, especially in cruise where one spends most of one's time. Leaning is done at all altitudes, BTW, otherwise you have a massive waste of fuel.
I'd like to see electrics too (I work in electronic & mechanical engineering) but the economic case has to be present.
They will also need to address battery safety issues. I know fuel is not that safe but it goes off only if you set fire to it. LIPO batteries often go off by themselves if damaged, overloaded, etc. and they release an awful lot of heat when that happens.