Somewhat? This voltage isn’t (just) about the battery, but about all power connections. Cables can only take so much current after all! At 150 KW, you need 400 V × 375 A. That is an insane current figure. At 800 V, it’s just half the current.

I’ve used a 300 KW DC charging station once. The cable is very thick and heavy. There are practical limits.