Yes, all fossil fuels are effectively "stored sunlight" however one of the problems with electric vehicles in particular is energy storage - even the best batteries still don't approach liquid hydrocarbons in terms of energy density.
People always quote this energy density thing, but this is a pretty moot point as I'd venture to say above 70% of automotive road journeys probably fall into the range limitations of modern EV's. Additionally taking only the energy density of the fuel and not the equipment to extract and convert that fuel into usable energy (a moving car) is probably a more accurate assessment of a fuel's usefulness for transportation, otherwise we'd be pushing for nuclear engines!
Charging time and vehicle price are probably the only current things holding back EV's in terms of widespread use (At least the only practical real issues, public perception is a whole other kettle of sharks). Your second point about using these hydrocarbons for plastics is pretty much hitting the nail on the head. The current state-of-the-art in bioplastics is honestly decades behind EV's in terms of competitiveness.
Energy density matters for planes in particular and although the vast majority of days driving require no more than a typical EV car's battery range there are days when you need 3X what the highest range Tesla can provide. You can't average these things anymore than a conventional car can average HP requirements and conclude a car needs no more than 20hp.
My point was that ALL the energy we use comes either from the Sun or solar processes (heavy elements) and that the fossil fuels and all other non-solar energy sources are hugely inefficient compared to even the cheap 15% solar cells we have today. Oil, for example, comes from organic material than gained it's energy from the Sun directly or indirectly by eating things that did. The efficiency with which the organic materials sequester energy is much less than 1% and then you have to wait many millions of years to get oil. With solar, you get 15% or more instantly -- no waiting.
The big drawback to solar is storage and while batteries are a way to handle that it will be a while before the lifespan of battery packs are practical. But, since about 2/3 of energy use is during daytime even if there was no storage solar could provide 2/3 of our energy needs not counting planes.
I expect that 50 years from now, if we haven't killed ourselves off by then, we will be producing about 50% of our total energy needs with solar panels on our roof with another 35% coming from large utility scale solar projects. Some of the energy produced from the large solar projects will be used to make clean fuel for things like planes. I would bet that by then the cheap solar cells will be at least 25% and probably more like 35% efficient. A home with 100m^2 of 25% solar cells could produce on an average day about 75-100kWHrs or energy and that would fuly power the average home and leave perhaps 25kWHrs for a couple cars.
Brian