"The borg decide to stop being dicks" would have been a great story arc contrasting the Federations individualism with the Borg's collectivism to do some introspection stuff. Like someone on the crew is going to voluntarily join the borg and a couple of borg are doing a cultural exchange doohickey and we follow each group considering the merits of being a giant robot brain network vs. being an individual. Then, idk, in the third act Geordi has to temporarily join the borg to unfuck the thermoclinic space toilets before the planet explodes and then once he's out he talks about the experience with Data.