Steam is like the Xbox Live / Playstation Network for pc, it has great community features and in my opinion the best digital distribution platform on pc. Unlike other distribution platforms *EA cough* you can download the games you own anytime and you are not forced in to using any unreasonable DRM.

Indie games such as World of Goo have really done well on Steam, if JJ2 was sold on Steam it would be a place the majority of people could buy the game any time. Steam always have a good deal on most weekends, it would only be a matter of time before Jazz had his own weekend deal and a lot of new people purchase Jazz and possibly join the JJ2 community.

Jazz becomes popular on Steam, Epic takes notice of the series once again maybe?

Either way I own the majority of the games legally and I would gladly buy it again on Steam, its one of the few games i keep coming back to over the years.