But we don't know which would win out, a small computer with a few gel-packs and a few isolinear chips, or a large one with a gadawful number of isolinear chips. Perhaps the Intrepid is just barely on par with Galaxy after the unfair advantage of gel-packs is factored in?
And to be sure, we don't even known that the gel-packs would be better than the isolinear chips. We just know that the Voyager has the gel-packs, and that she is a new ship. Perhaps the packs are cheaper and thus preferred, even though inferior otherwise? The technobabble at Memory Alpha isn't canonically supported...
Actually the Intrepid class incorporates gel packs WITH isolinear processing unites. The gel packs are artificual nueral fibers that simulate how a brain functions, allowing quicker response time. The Sovereign class also incorporates this technology.