I've been using linux and the command line since the late 1990s, and I never knew about the Ctrl-l. Thank you!
From here:
Clear The Terminal • Linux Tips
Today's article will be a nice and easy article, where we learn how to clear the terminal. That is, we will clear any typed text.
linux-tips.us
The difference between clear and CONTROL+L is that clear overwries the last command’s exit code ($?) with its own, 0, whereas CONTROL+L doesn’t –it is not a command, but a terminal emulator shortcut.
So, there's what's going on. Someone left it as a comment when I wrote a similar article. I knew that it was a shortcut, but didn't really know what clear was doing.