I remember Jannetty being a good in ring performer, I dont remember him having much charisma or ever showing much nuance with his character. To me it's clear he was the "other guy" in a team where one guy was great and the other guy was just great at complimenting him. HBK had charisma and as he improved on the mic he made a phenomenal transition from teeny bopper tag team guy to full fledged Ric Flair like heel, arrogaunt, over the top extravagant, a complete transformation that he pulled off well. Jannety never showed me anything that made me think he could have done that regardless of his drug issues.
I put him alongside Robert Gibson (great in ring worker, lousy promo guy) who was a stand out side kick for Ricky Morton in the Rock & Roll Express (the mega popular 80s tag team that the Rockers were created as immitations of) and Jim Neidhardt (never Brett Hart's equal in ability but a solid companion during the Hart Foundation days) in terms of his own individual star power and ability vs how good he played the 2nd fiddle.
Now some teams dont function like that. Tully Blanchard & Arn Anderson were a great team but both were seasoned singles stars, Blanchard a bona fide main eventer in his own right, before they teamed. Hawk carried the promos for The Road Warriors but never outshined Animal by the wide margins HBK did Jannetty or Hart did Neidhardt. HBK & HHH were great together also but clearly there was no one stand out between them.
If Jannety had kept himself clean, working in an era when Vince was giving smaller, more athletic guys more of a push than in the past, he likley had enough in ring skill and name recognition from his tag team days to have had a solid run in the mid card, popping in and out of the IC Title picture, and if all else failed likley could have gone to WCW and played a similar role for a slightly better pay check. I just done think he ever would have reached the heights HBK did because he wasnt the total package. He had the in ring ability but he lacked the charisma and mic work. He was good enough to have survived, especially with two major companies both with great national TV exposure, but he wasnt good enough to thrive.
At the very least I think we could have gotten some very good matches with him vs Brett Hart, Scott Hall, Sean Waltman, and if he went to WCW I think he would have worked well with Flair, Arn Anderson, and some of the mid carders like a young Eddie Guerrero or Rey Misterio, Jr.