I've maintained both kickstart and ignition professionally. The documentation and readability of Ignition is absolutely way better than kickstart.
A simple example would be downloading a binary file and checking it's hash during boot, with retries if the connection is flaky. Three lines of declarative state in Ignition vs complex scripting in kickstart.
Ideally one uses mainly kickstart commands to configure the system during the installation - then the installer (Anaconda) takes care for everything for you. If you use custom scripts with kickstart, you are pretty much on your own, like with any other custom script.
BTW, maybe open an RFE to include a helper script in the installation environment for easy & robust file downloading ?
https://pykickstart.readthedocs.io/en/latest/https://access....
Any concrete examples of stuff the existing docs do not cover ?