[Stratoscope]

But the arrow cursor is not used for selecting text. The cursor switches to an I-beam over selectable text.

This was the case as far back as the original Mac; I'm not sure which cursors were used on systems before that.

[thwarted]

Not all on-screen text is selectable!

[oneeyedpigeon]

And that's a problem at least an order of magnitude more serious than which few pixels the cursor is covering.