Are PTC's A Thing Of The Past At The High School Level?

In recent years especially in the spring PTC attendance at my school has dwindled to a very small number of parents.  This has gotten to the point where teachers are asking if they are necessary and thusly be eliminated or can they be squeezed into 1 day.  With online grade books and with phone/email access to teachers are they really necessary? Please leave your comments below.