Which USB to RS-232 serial drivers are installed by default on macOS? In macOS 10.14 Mojave and 10.15 Catalina, are there any USB to RS-232 serial drivers installed by default?
macOS 10.14 Mojave

Running the following commands, I found FTDI, but there could be more.

$ cd /System/Library/Extensions
$ ls | grep -i ftdi
AppleUSBFTDI.kext