hellokitty11583 TeddyRoses It is not accurate to say that this version of Sims 3 is completely unstable. It certainly has its issues, but the issues are mostly about gameplay and visuals, not crashes. It is absolutely possible to get the game running reasonably well and to avoid the few known triggers for crashing, for example the rock wall from the Store is always a problem.
This isn't just speculation or third-hand info; I myself use a Mac as my everyday computer and frequently test Sims 3 on it. I do play in Windows when I want to play my own game, but that's because of certain features that don't work in macOS and because the game stutters a lot more, not because it crashes.