Players within command blocks cannot select the previous output text field using only the keyboard, meaning all but the very end of long output cannot be seen.

For example, the output of the following command is very long:

give @p dirt{display:{Name:'{"text":"<this text cannot be seen by keyboard-only user>xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"}'}}

Due to players not being able to navigate to the previous output text field with the keyboard, the cursor cannot be moved to the beginning text for the player to read it.