He's right but it's only in optimal condition where you can get cheap rate electricity. Driving in London is very efficient for EVs, you can hit 5mpkWh with ease since traffic is so bad. To cover 100 miles you only need 20kWh, at 5p/kWh off peak charging it's £1/100 miles. Equivalent petrol/diesel at £1.9/l and 55mpg is about £15/100 miles.

For public charging the rate is several times more than 5p/kWh, equalising the numbers somewhat.

It's not, it's about half as I did this exact calculation a couple of days ago in a new car discussion with my partner (charging works out to ~£0.49 per 4 miles, we're currently ~£1.05 per 4 miles for a reasonable mpg car driven primarily urban crawl)

though note that thats retail charging, home charging is half that (about £0.25p per 4 miles)

I suspect the issue is more that car companies can't make enough EVs for demand. I recently had a similar problem and ended up with an ICE car to avoid year+ wait times