CFI is the high road and I'd push anyone in that direction first if you really must choose. The problem is that most pilots who go that way never bother with anything else in their pursuit of hours and an airline job. They really miss out on something when they do so. Some of the most rewarding, enriching flying is definitely stick and rudder jobs like skydivers, pipeline, surveys, glider-tow, aerobatics and banner operations. I really urge you to do all that. I see a strong push on career-track pilots to become an airline pilot as fast as possible as though the latter summarizes and consummates all other flying jobs. This is a flaw in the domestic flight training system. But it is not so, and while airlines often have some of the best pilots on staff they also are not the only career destination, and even if you choose airlines in the end, you will be more roundly experienced if you did some other things first. I recommend that you teach basics for a few hundred hours and get your CFII, go to work for an aerial applicator for another hundred or so, get a job flying 135 freight for a year or two, and then apply to a regional airline if that's what you wish to do. You'll be a better pilot and you'll know what the difference is.
As for the career and its prospects for the future in the US, read the US Bureau of Labor Statistics on the subject.
Airline and Commercial Pilots : Occupational Outlook Handbook: : U.S. Bureau of Labor Statistics