I started my own business also. I believe it depends on which airline you fly. For example Southwest grew rapidly since 9/11 while most of the mainstream airlines wilted. SWA now flies more than half of all the passenger-miles flown by US domestic air carriers. This allowed them to upgrade to the latest B737s. Their aircrew, flight attendants, etc. seem VERY happy to be with SWA.
By contrast, other US domestic airlines that are still in business e.g. Delta have obviously unhappy aircrews and flight attendants. This is true with many struggling airlines around the world (the ones that are still in business).
As for empty seats, you won't find them often on a successful airline like SWA.
The good side of this is, the price of air travel has gone way down. I can do a 2 week advance purchase round trip flight from NH to Baltimore Washington, non stop including a MARC train ride to Union Station in Washington DC for around $120 round trip. This allows my business to NOT have a Washington office. We work from NH.
Even recently, with the HUGE increases in the cost of jet fuel, the airlines have been doing a fairly good job in keeping the prices under control... This in part is due to new technology in the newer planes, such as the wing tip "winglets" and upgraded engines.
If you have noticed more flight delays since 2001, that's likely due to the new weather radars installed at all US airports in the last few years. These new radars see "microbursts" (violent, invisible air pockets which have caused many crashes) where they could not be seen before. For better flight safety, the air traffic controllers and tower staff are now able to hold off landings and take-offs when microbursts show up near airports. This might mess up flight schedules but IMHO I'd rather be safe than dead.
Yes there are some highly publicized delays caused by airline "screw ups". Some of these are a product of the economic difficulties these airlines are in. They may reduce maintenance on older airplanes which they can't afford to replace. That goes back to my "it depends on which airline" comment earlier...