Theoretically it will dramatically increase charging speeds. But that only helps on the road.
Of course there is no 800v charging out there... So what good is it?

 

The 350kw stations are 800V charging stations.

 

And Electrify America is expanding the number of 350kW chargers. When I drove to SoCal I mainly used the 350 kW chargers

 

EA has a ton of 350kw stations in California. I'm seeing a lot more Ioniq 5s and Polestars around too (also waaaay too many Teslas). You don't need an 800V architecture to get fast charging speeds though. Tesla is able to get very good charging speeds using its 400V architecture by juicing up the amps at the V3 stations (I believe up to 800amps). I think its easier though to get faster charging speeds by increasing volts though and the 800V is probably the optimum way to go as an industry.

 

So am I. I now daily see Ioniq 5 and EV6. I occasionally see Polestars but are seeing more and more in the wild. The Polestar is still unique enough where it arouses curiosity, today a guy in an M5 pulled to the side of me and put his head out the window to read the Polestar label just behind the front wheels (the only identifier of the brand). He looked at me a little embarrassed and I just smiled. Of course the lions share on the road are the Tesla M3 and Y. I don't think I can even keep count of the number I see daily. It is just as common as any Toyota, Lexus, BMW and Mercedes