Ideally there are no harmful combustion byproducts when used in ICE, the reality is probably less harmful combustion byproducts, not none Hydrogen is lossy, Conversions being inefficient, Molecules small enough to migrate from containment, Embrittlement of pipes & tanks
3 or more times the infrastructure per watt delivered, a huge investment in resources
I suppose if there is excess generating capacity, hydrogen could be used as a storage medium for night time

Oh great, punch more holes through the aquifer that can’t be repaired

Creating wealth is not building value

Qrs don’t seem safe to me
Scanning a Qr allows the installation of malware apps so I can look at a restaurant menu, & ding my card for recurring charges?