This seems to get less discussed. When I was travelling home last Sunday after the Thanksgiving, I had to stop for a supposedly splash and dash style supercharging at about half way. It was a 20-stall Supercharger V2 site with 150kW max supply. I should just plug in and leave in about 5 minutes. Luckily the site was not entirely full when I arrived. It had 2 open spots, with another one broken. I plugged in as usual and I had only 25kW charging speed. (Preconditioned battery and lowish SoC, should accept 100+kW.) I switched to the other open spot and again I had 25kW. At this time, one car left, and I moved over to the spot and not surprisingly I got 25kW.
So I bought a cup of tea and waited for about 30 minutes. Shortly before I left, I think the other car from the same supercharger euiqipment left and I charged at 50kW for a few minutes.
I figured this was because after a full day of high usage, the batteries in the Supercharger equipment was depeleted. And because of continuous usage, the charger battery had no time to get charged. The grid feeding power seems to be just 50kW/equipment. With 2 cars sharing on equipement, each gets about half of that.
It's a shame that there are a number of EA 350kW DC chargers along my route and I cannot use them (Model 3). I really hope that Tesla releases inexpensive CCS adapters. (Or a single standard around the world which is no hope.) With more and more Teslas on the road everyday, I'm not sure if the Supercharger network can keep up. Being able to charge at other locations is better usage of resource and helps encourage infrastructure investment. I prefer the Tesla charging connector but Tesla U.S. may need to move to CCS, similar to what they do in Europe and China. (I think Chinese Model 3 has 2 charging ports, which could be very handy here.)
I'm just sharing my experience, not complaining. I know what to expect and I still like my car. Cheers.