couple thoughts....
How much more petroleum would be used if we DIDN'T switch the fleet to electric?
Also, electric trucks are coming to market right now, with Tesla leading the way, so IEA might be behind the curve there, five years ago, thinking there are no alternatives. There's also biodiesel. And fuel cells, fed with electrolytic hydrogen. And aviation is not a fixed thing, either, as highspeed train options may divert some passengers to a safer, less-hassle, ground-based mode of transit.
We will probably still use petrochemicals, but not for burning so much.
As for getting your scientific estimates from EXXON, lol!