We can pretty much stop at CCS for all that it currently matters. CCS supports a software protocol for negotiating AC/DC/current/frequency and a wider variety of options than are currently practical in most states. CCS is like a super-over-designed-by-committee USB-B+. (It's not quite USB-C because it is definitely not symmetrical and insertable in any orientation; it's backwards compatibility with "USB-A" level two ports alone insures that.)
CCS supports "Plug and Charge" as a protocol handshake, and that's really indicative of the actual fight happening in "plug" designs for cars and the proprietary network: Apple Pay (Tesla Supercharger and what CCS could be if networks support it) versus your Old Fashioned Credit Card Swipe machine. Everyone is fighting to get more of those Credit Card fees and letting the ideal (plug in and the car knows how to bill everything) get in the way of the practical (credit card swipes have mostly worked for gas pumps for decades). It's a very dumb fight that is getting in the way of practical adoption.
It is a great benefit to society that our transport recharging (gas dispensers) are standard in design, so that any company can operate a dispenser of any vendor into a car of any design.
The same should exist for EV - but if the "least common denominator" becomes obsolete, allow vendors to provide a secondary (or tertiary) mechanism to charge. Yes, this increases initial production cost. Yes, it is worth it for the benefits gained to open infrastructure.