11. The XBs
Star Trek: Picard spent an inordinate amount of its first season cutting away from Picard himself to Soji and Narek's "romance" aboard the Artifact. The setting itself was promising... a derelict Borg cube under the command of a shattered Romulan state, full of former drones or XBs, including "I, Borg" himself, Hugh.
Sadly, much of that promise was ancillary to the plot and while Star Trek: Picard centered around Picard (a former drone) and also featured Seven of Nine (the most famous of all the ex-Borgs), the XBs themselves didn't seem to really have much to do in the first season.
Aside from their inclusion in the Artifact-centric episode "The Impossible Box", the ex-Borg drones' promise as a reflection of both Picard and Seven's past, as well as a new take on a legacy Star Trek villain, and their peripheral relationship with the overarching plot revolving around artificial life, the XBs were sadly wasted. And even after Seven lead the XBs in a mini-revolt against Narissa and the Romulans, they disappeared entirely before the end of the season, crashed on Coppelius but... who knows?
Deleted scenes from "Et in Arcadia Ego, Part II" apparently depicted Ramdha and the other XBs going on to live a life of peace with Altan Soong and his hippie android children, but those scenes and any reference to them were sadly omitted from the episode as aired.