CCS is rated to 500A continuous which is really the bottle neck and push for 800V for decent sustained rates, not like the 250kW spike and tail down like the Tesla's with their 400V limitation presently. isolation within the power electronics becomes harder with higher voltage to prevent arcing too so its not a free lunch. Taycan of course does the opposite of what you have described, contactors added for the 150kW option on DC 400V rather than standard 50kW, Splits the 800V pack into two 400V units
It will come anyway, 900ish as a cap on passenger cars as per Lucid, anything over 1000V will be for commercial stuff as it requires professional drivers to ensure the appropriate training and license to operate 1kV machinery.