The downside to Technology and being updated about your flight

When you sign up for updates on your flight be it via your cell phone or computer notifying you that your flight is delayed most of the time it is because of ATC Air Traffic Control delays, these delays are and invariable do change several times over the course of the day and when the Aircraft has already arrived at the departure airport you better be there when those changes occur as you will miss your flight, for example you have a flight from West palm beach PBI to Newark EWR AT 330PM, at 11am you are notified that the flight has been delayed until 530pm so you decide to arrive at the airport at 430pm, plenty of time right ? well no because if the Aircraft is in West palm beach at 230pm and at 330pm it is released then it boards up and goes, you arrive one hour later only to be told the flight departed, read the small print at the bottom of the notification, it says SUBJECT TO CHANGE and it will ! this is not the Airlines fault but rather the stressed out Air traffic control system that we have in this country.