It’s an engineering-tradeoff. The efficiency losses in hydrogen production are offset by the ability to refuel a hydrogen tank in under a minute compared to the hours it takes to safely[1] recharge a BEV. Plus, if hydrogen fuel production is powered by environmentally friendly electricity then the efficiency losses should only worry people concerned about the heat-death of the universe (and it’s no worse than the 20% efficiency of an ICE engine. “Don’t let perfect be the enemy of good”, etc)
[1] While Tesla’s V3 Superchargers are amazing in that charging stops can now be as short as 10-15 minutes to for 100+ miles of range - Superchargers should not be used for day-to-day charging because it wears out the battery too much (hence the hype over the new generation of Lithium cells, that “million-mile battery”, but for the rest of us using current-gen Lithium batteries (myself included, I drive a Tesla too) I don’t want to have to drop $20k+ for an out-of-warranty battery replacement).
