Rick's an odd character for Marvel. He's bounced around a bit in search of a "home". I think he was something Kirby (who had more of an affection for kid/teen characters) brought to Hulk rather than Lee. Lee was on record as disliking kid sidekicks. When the Avengers came along Rick was along for the ride. Again, probably more from Kirby's plotting than Lee's. When Kirby steps away, Rick is pretty much finished with the Avengers. Over in Captain America, artist-plotter Jim Sterenko seemed to like Rick and tried to make him into Bucky 2.0. When Sterenko left, Rick was sidelined. Roy Thomas who was a big Golden Age Captain Marvel fan, brought Rick back to serve as Mar-Vell's "Billy Batson" when he revamped Captain Marvel. I think he wandered back in the Hulk's sphere under Peter David.IGN has new article up discussing something I've been wondering about with the MCU.
Whatever Happened to Rick Jones
It has seemed odd to me that a character who's been such an important part of the comics, hasn't shown up in the MCU at all. I can understand not wanting to include him as a teenager, but they could have done the same thing the movies have been doing characters like Bucky or Jimmy Olson at DC and just introduce him as an adult. Maybe he could have been Bruce's lab assistant during his gamma radiation experiments or something like that.
The article is right that the MCU missed its chance use Rick in all three of his comic's partnerships. Especially in the Marvels' corner which was IMO where Rick really shined.