That may be, but Occam's razor suggests that it would be a good idea to ask why that still hasn't been done. Surely there are some reason why such obvious and useful things still haven't been implemented, right? I may be wrong, but i'd like to suggest that there are certain interest groups behind all of that, for whom such changes would be bad for business.
Also, what makes you think that both approaches couldn't be utilized? Use less resources, increase taxes to compensate the drop in prices that would otherwise follow and gradually stop subsidizing things like meat production, at least to the degree where the price at stores is artificially lowered. At the same time, attempt to subsidize wind, sun, geothermal, nuclear and other forms of getting electricity and see whether things are better or worse in 50 years.
Those approaches are not mutually exclusive, as long as you have plenty of legislative bodies on your side. Sadly, we don't and probably won't, at least until a generational shift takes place. As Planck's principle states: "Science progresses one funeral at a time", which could be attributed to social policies to some degree as well.
Of course, in regards to electric vehicles, one also has to consider the necessary infrastructure to support them and what's the CO2 cost of creating their batteries in the first place. For a while, and certainly in some geographical settings, hybrid vehicles could also be good for a gradual transition.