A modern combined cycle power plant is significantly more efficient than a typical internal combustion engine, even when taking into account transmission losses

A modern combined cycle power plant is significantly more efficient than a typical internal combustion engine, even when taking into account transmission losses. So, an EV is going to use less fossil fuel per mile, even if the power plant is fully fossil fuel based. On top of that, per megawatt, building out new solar is cheaper than keeping existing coal plants running. The solar transition is largely constrained by the duck curve, which can be mitigated using v2g technology, so as time passes, the power sources get greener out of purely economic considerations. As long as you're not throwing out brand new ICE vehicles and just replacing worn out ones, both the TCO and the total carbon footprint goes down when switching to EVs.