At the time VOY premiered, DS9 was only in it's 3rd season or so. It hadn't really become serialized by then.
In fact, there wasn't that much successful serialization (especially of a genre show) around in 1995 that Paramount would risk it. ENT doesn't have much of an excuse, and it DID become more serial as it went on. But VOY really wasn't that much "stuck in the past" as detractors say.