It's rarely cost effective and there are lots of hassles and complexities that can be just as bad as airport security.

However, there are plenty of times when it's more convenient. Especially for short trips where you're in and out in a few hours and there's an airport nearby where you're going. Or if 2 or 3 people are going, the value is much better.

Most practical trip I do is Jacksonville to Tampa and back. It can be a 3 or 4 hour drive, but it's about a 80 minute flight. I use CRG in Jacksonville and X39 in Tampa, both are within a few miles of where I want to be. It's totally viable to have breakfast in Jax, fly to Tampa, be there for 6 hours, and then head back and have dinner back in Jax. Try doing that with a 3 hour drive on each end or going through security to take a "continental connection" flight, etc.

Longest trip I've done is Austin, TX to Jacksonville, FL and back. Left the morning of July 2nd, returned the evening of July 3rd. It was long.