This is not scalable with the current grid infrastructure and will destroy grid equipments via the accentuated grid harmonics.
They aren't a tricky engineering problem to solve - but nobody is too worried about solving them right now because the people who maintain the grid and who have to deal with harmonic losses aren't the same people as those who design the charger.
It's not as bad as you might think because replacing old chargers is easier than replacing all EVs.