Total UK electricity consumption is around 300 TWh annually. That would put the grid losses at less than 10% based on your link. The charging is never as bad as 25% (internal house losses are negligible for any sensible charging rate) and the car is typically ~12% charging loss. Moreover, EVs recover quite a bit too. Even in purely dissipative driving (highway driving), I get around 4 miles/kWh, which is about 4 times better than an ICE vehicle.

Furthermore, if you're going to include distributional losses, then let's also drop the available petrol by 10-15% to account for refining etc.

Finally, on anything resembling a sunny day, my car charges entirely of rooftop solar, so what efficiency do we assign to that?