[HandyAndy]

Once an EV's weight goes (well) above 2000 kg, you're well into the region of diminishing returns.
I can get 200 miles in summer easily in my Ioniq 38 ~1600 Kg, about 42 kWh total, but 38.3 kWh usable.

When the Ioniq 6 came out, with a lower Cd drag coefficient & 2x the battery capacity and improved efficiency in the motor's electronics, I wondered if we'd see that car get close to 400 mile range. I don't think any of those owners are getting 400 miles, ever. Around 360 seems to be about the best they can do. Good, but you can see the effect of a heavier battery - larger tyres needed = more Rolling Resistance etc.

Keep this trend up, and you have the new Rolls Royce Sceptre EV, weight about 3000 Kg, battery 102 kWh usable, highway mid-weather range 270 miles (info ev-database.org). Wasteful & inefficient in my book.