This really gets to usability. Most scientific calculators I have owned have a y^x key AND a √ key. Most have a cube root key as well. √ is a very common operat

This really gets to usability. Most scientific calculators I have owned have a y^x key AND a √ key. Most have a cube root key as well. √ is a very common operation and with its own key can on many models be applied to a result with a single key press (it often works immediately and the = is not even necessary.) y^x to indicate square root can be applied to a result with ^,0,.,5,= -> 5 key presses, or 4 if continuing without having to finalize the calculation. Given that √ is a common operation, 4 or 5 key presses for it is pretty ineffective compared to 1 key press.