If you think the problem is not coming up with new villains, then Jar Jar wouldn’t be a good option either, given that he’s already an established character.

I do agree with your basic point though. If I had it my way, the villains of IX would be the Knights of Ren. After returning from some sort of expedition into the Unknown Regions, they begin to harass Kylo for not following their code of honor. This feeling of isolation eventually leads Kylo to join the Resistance, although they obviously don’t trust him at first. After that, the Knights take over as the main villains, and the climactic duel is Rey and Kylo vs the Knights.