Health and safety implications? Infrastructure? Why is London unlikely to have 415V 3-phase power available? All nonsense.
With the exception of residential properties, power is supplied using 3 phases. It's generated as 3-phase, and until the final step-down transformer, that's how it's transmitted. There may not be outlets, but any building of reasonable size will have single-phase outlets supplied from different phases. HVAC equipment, lifts, etc will all be supplied by 3-phase. To supply a whole building from a single phase would result in unbalanced currents in the 3-phase supply.
If the charging time is 5 minutes, how would it be any different from a busy petrol station? Waiting 5 minutes to start filling is hardly unusual!
"Rockets are just another name for trouble. Either you just had trouble, you are having trouble, or you are going to have trouble." - Milt Rosen, Viking Program Director, White Sands Missile Test Range