

VOY had a similar problem. Tried the Kazon, the Vidiians, the Hirogen, a few one-offs, and then back to the Borg once the Queen concept had been established. The main goal of reaching home over such a distance left them leaving behind any credible ongoing threats. Why else create the transwarp network if only to allow the Borg to become a consistent nuisance?
Only telekinetic Vorta come from the Gamma Quadrant, otherwise they’re just sparkling Vorta.