As mentioned in this post running font-family: Arial, Helvetica, sans-serif;through fontfamily.io reveals that Helvetica is never used.
Possible alternatives:
Ditch Helvetica and only reference Arial to get the same result with less CSS
Put Helvetica and possibly Helvetica Nueue firsts to take adavantage of it (debatable because of the complexity of font-rendering on different systems)
As mentioned in this post running
font-family: Arial, Helvetica, sans-serif;
through fontfamily.io reveals that Helvetica is never used.Possible alternatives: