But that forces me to move to another key. If I’m on the last line and press the down cursor key, it’s obvious I want to go to the end of the last line.
Several other text editors have the behaviour and it’s useful.
One caveat though, if on last line and down cursor key is pressed, the cursor should move to the end, but the current cursor X position should not be updated, so if I do Up cursor key again, it should move to the X position that it was on before it was moved to the end. For example, suppose I have two lines:
123
ABCD
and the cursor is between B and C. Pressing down should move cursor to end (ie. after D), but pressing up cursor would move cursor to between 2 and 3. Only a left/right cursor should update the cursor X position.