I don't understand why people think removing an onboard charger...

I don't understand why people think removing an onboard charger makes so much difference. Something that plugs in to a standard Australian outlet is limited to 2.4kW. It's not much, but it's enough for many drivers who will overnight charge for 10+ hours and only commute less than 30km.
It's also fundamental basic feature (minimum viable product/feature) to be able to plug in pretty much anywhere you stop in a residential context.
Now, do a quick web search for a 2kW rectifier module for any common 48V DC system. Whatever changes need to be made for the car battery voltage and so on won't be significant. Then think about how little space and weight it takes up compared to almost anything else on a car.