True. But sometimes it is a matter of convenience. On a recent road trip, we had to take a 'bio-break', and there was a Chargepoint CCS site nearer than the next Supercharger site. So once again by overlapping the two, it saved some time by eliminating a Supercharger stop further down the road. (Won't happen again at that particular site, Redding CA, as a new Supercharger site is almost completed literally right next to the Chargepoint site.)
There are also getting to be a lot of CCS sites in rural locations far enough away from the Supercharger network that the other alternative would be slow L2, or even slower L1, charging.