Thank you, this is really helpful info. I'm usually good at following instructions on tech stuff but am not that skilled/knowledgable on any of it myself. Before I removed all the sims games from my mac I still had some storage left, but very little. However, based on your response I think you're correct moving the files to the external drive probably wouldn't have fixed anything. The performance issues started when I downloaded a few new packs, so it sounds like the issue wasn't about storage but that my hardware wasn't robust enough to handle running the game with that many packs. Am I understanding right?
In that case, would the best solution for being able to continue playing the game on my laptop without the same performance issues be to still have the game and packs installed on my device since I have the space, but not download all the packs I was previously using and leave some uninstalled so the game doesn't overwhelm my hardware? (I'm planning to upgrade to a gaming PC at some point, just looking for an interim solution that allows me to play the game without killing the mac)
Yes, when I said get all the files on the external drive I meant all my packs and kits. I've gradually accumulated a lot of them and the performance on my mac was okay for a while as I kept adding on, but after the last two or three expansion packs there started to be issues.