Yes, for learning, I think this version is also a suitable start. At present, we also integrate ROS2 related learning examples, which are basically suitable for later versions.
We will also migrate to the humble version in the future.
At present, the custom image based on cubic is not well supported by the humble version of ros2 and the backup software based on systemback is not well compatible with ubuntu22.04
I haven’t tested other effective ways to make ISO images yet