There are? Here in UK you have Type 2(can be safely ignored for this, pretty much only used for at-home charging up to 7kW single phase or 21kW triple phase), Chademo(only used by the leafs and other Nissan cars) and CCS. CCS being the most common, there are motorway charging stations with super modern 250kW chargers and they only have CCS, so no issue with compatibility at all. Basically all new cars have CCS connectors, it's the standard.

And yes, CCS supports either 400 or 800V charging, but that's seamlessly negotiated by the car once connected, I don't see that as a problem here.

A large truck will not be able to use a CCS charger even at 800v for under an hour. The Tesla semi look to be using a special connector with 4 parallel DC connections while a CCS2 is only a single pair.

Your going to need a Megawatt for reasonable charge times, CCS tops out a 400kw at 1000v and 400amps with liquid cooled cables and connectors.

BTW a diesel truck pump puts out about the equivalent of 6 megawatts after efficiencies are normalized.

Like I said in another comment - commercial drivers have to stop for 8 hours every 8 hours of work by law anyway(in UK/EU), so there's plenty of time for charging. Even at the relatively common 150kW charging speed you're charging 1.2MWh(!!!) Capacity every 8 hours. I really don't think trucks will come with megawatt-hour capacity batteries, but if they do then 8 hours are long enough to charge such a battery with infrastructure that exists today.

Tesla is claiming "under 2kwh/mile" for their semi. At 2kwh/mile your looking at a megawatt for 500 miles range which is close to an 8 hour drive.

There will need to be stall where a semi can park for 8 hours using a charger.

Local deliver makes sense also city buses obviously and thats already happening. Long haul will need a lot more charging infrastructure to make sense.

In the US there is J1772 that works on everything and it works with 120v - 240v up to 80 amps (though typically 40 max).

The US has settled on CCS type 1 for fast DC charging, most new cars support it.

There is CHAdeMO a Japanese standard but that connector is on its way out in the US.

And then Tesla does it's own thing but there are adapters available.

I think it is a solved problem, if you don't want a Tesla a modern EV will have a CCS plug that fits both CCS and J1772. And if you want a Tesla you either get adapters or use Tesla's chargers.

The biggest unsolved part of EV IMO is the fact that mining lithium destroys the environment, and IIRC uses a fair bit of child labor. Looking at it from that perspective it’s not yet a green technology.

Lithium mining is pretty well industrialized I think.

Cobalt mining has problems with child labor.