No character development
It's funny that I'm able to watch and enjoy all 7 seasons of Mission Impossible without ever knowing anything about the main character's lives or personal motivations. Outside of their individual skill sets and the (apparently true) names they go by, they're given zero background. I don't think we find out who or what the IMF actually is either. It's easy to assume they are American government operatives, like a CIA funded group, but at no point in the show is it ever made clear. We just know that "The Secretary" is giving this team missions, men and women who are essentially professional con artists. I remember in one episode a woman asks Jim who he works for, and he tells her "Sector 17" ...or something along those lines. But considering he's in the business of illusion and deception this suggests he's probably lying. MI powers along on the pure strength of its episodic plots, themes and style alone, that's pretty clever and unique.
BTW I never watched the '89 revival series because I heard it's pretty bad. Is it worth watching, and do they explain away all of this stuff?