Hydrogen vs. Battery Electric Cars

The new Toyota Mirai weighs 1,920–1,950 kg and has a range of 402 miles. The Model 3 Long Range weighs 1,829 kg and has a range of 353 miles. The Model 3 is much faster too. Your plot does not reflect the current market offering, nor does it reflect theoretical maximums.

Model 3 Standard:
1672 kg/263 miles = 6.35 kg/mile

Model 3 Long Range:
1829 kg/353 miles = 5.18 kg/mile

The slope of the BEV curve should actually be less than a linear increase in the region that was plotted. I understand your point; it does become greater than linear at some point, just not at the point of current BEVs.