Yeah, the physical singles market basically disappeared in the mid-aughts due to digital (this point was illustrated in the excellent
All Things Must Pass documentary), which is why Crocodile was the last single with a CD release.
Every single since then HAS had a CD release. They're just promo CD's only though. Most of them are even pressed/replicated CD's and with proper sleeves/artwork. Only a couple were CD-R only (Holding the Moth, Baby Wants to Ride).