This entire discussion of flying vs. driving started because people did not want to have to pay $500 to rent a car for the week or pay for constant ubers . . . not because it's faster to drive. Obviously no one will argue which method is faster.
It all depends on what you can afford and how much time you have.
The conversation diverted to that when a PP said that it was "lame" to fly when you live within 7-8 hours driving distance. But to your point, I could argue that paying for multiple Ubers is likely still cheaper than the cost of gas, wear and tear, rest stops, and potential additional hotel rooms that one may need to book depending on the length and timing of the drive. Even if the difference in cost is negligible or slightly more by using Ubers, I would much rather pay for the Ubers for peace of mind so I don't have to worry about traffic, directions, parking hassles, I can get dropped off near the gate, and I can have as many drinks as I want.
7-8 hour drive from Atlanta to Orlando. Eat what you want, stop when you want.
Versus...
2 hours in the airport. 3 hour flight. 45 to 90 minutes to deplane, get luggage, get transportation, etc. Trapped on airplane and in an airport for 7-8 hours.
Tell me again how you can't afford to lose an entire day of vacation on both sides of driving.
This is how I'd estimate the time differences you're suggesting.
Driving Atlanta to Orlando:
7am - leave the house
11am - bathroom/lunch break/gas
11:45am - back on the road
2:30pm - bathroom break
2:45pm - back on the road
4pm - Arrive at Disney resort after driving through rush hour traffic
This scenario leaves you with an evening at whatever park or Disney Springs, but there's a good chance a person may be tired from the drive and will want to call it an early night.
Flying Atlanta to Orlando:
7am - leave the house
7:30am - arrive at airport (obviously a huge variable depending where you live)
9:15am - flight from ATL to MCO
10:45am - arrive at MCO
12:30pm - arrive at resort (average DME time is 90 minutes, but even renting a car, I'd estimate the same)
This scenario gives someone an entire afternoon and evening at whatever park they want, and chances are they are less worn out since they are simply sitting on a 60-90 minute flight rather than focused on driving for 7+ hours.
Obviously, there are lots of variables with both scenarios - you never know when you'll encounter traffic jams, construction delays, delayed flights, long DME lines. All of these things are out of a person's control. But I would still assert that flying even when you're within 8 hours driving is the faster option. Budget and the amount of time you have for vacation will influence decisions, but it doesn't change the timing.