In the UK I could get from Central London to Central Glasgow in 4.5 hours on the train. The same trip on a flight, it takes an hour to get the airport (assuming it's not one of the budget airlines pretending Essex or Bedfordshire is London...), I need to be there 2 hours before (maybe less is you are brave and Security isn't messed up) the flight takes an hour and then I have to get out of the airport and find my way from Paisley back to Glasgow Central.

Of course there are a lot of variables, if instead I leave from my house the aircraft would actually be faster, mostly due to the extra time it takes to get to Central London and from Waterloo to Euston.

In reality we usually drive in about 6-8 hours because, as a family of 4 traveling, it's considerably cheaper even before you take into account having transport on the other end.