If you can't really think up a PIP topic that's super 'personally interesting to you', I'd consider dropping the subject tbh. Having recently completing the PIP, I honestly have a tonne of regrets keeping it through year 12. I chose to write about ethnic communities and identity, which was kinda interesting and suited my interest in geography, but part of the choice was down to something that looked 'academic for the markers'. During the process, the PIP turned into just a P (project) for me as I really didn't care too much by the end of it. Similar to yourself, I would say that I'm really not super passionate about social issues/social justice, so I didn't really gain much out of the PIP process. However, my peers that were very into their topics produced some solid work and they'll do pretty well.
But that being said, it's also dependent on your HSC/ATAR goals. If you're not too worried about squeezing in more marks, just pick a topic that you're interested in and slowly put an alright PIP together on it, because at the end of the day, for me, it wasn't really worth the stress and the sleepless nights, but the research process was insightful and somewhat rewarding.
What are your other subjects? If you've got another major work/difficult subjects, I'd abandon the PIP lmao, but if you're not too worried about everything, brainstorm some topics, watch the news, read the textbook, and come up with an area that you would want to inquire into.
Good luck on your PIP process (if it eventuates)!!!