There are certainly fleets that need rapid charging throughout the day and they will need expensive DC units. There are many fleets that only need lower speed, longer duration overnight charging at the fleet yard. Native 3 phase with load sharing charging hardware is the lowest cost way to achieve that. No need for expensive labour to move vehicles or power connections overnight, much lower installation cost than even the smallest DC charging hardware, and no need for expensive 400+V DC certified electricians.
If you need charging above that, especially at fleet level, it is cheaper to go with dedicated DC charging like the one's I linked. 48A single phase charging is more than enough for the vast majority of all EV use-cases, even for fleet vehicles. Amazon has the largest EV fleet fielded right now, and that's in the US.
You're complaining about a non-issue. Three phase AC EV charging is a solution in search of a problem.
Commercial fleets in the US will use 3 phase for DC. For commercial installations, this is a non-issue [0]. It's more efficient to use DC charging at scale than reside on the vehicle's onboard rectifier.
>I think north america is going to regret not having 1st class support for 3 phase charging baked into all electrified vehicles in the long term.
It's already here... Where are you getting your information?
[0] https://www.eaton.com/content/dam/eaton/products/emobility/e...