hey guys, if you're all wondering why steam isnt opening on your macs, you need to use an app called 'Whisky' so you can play windows games too, after that you have to pin SteamSetup.exe, run it, install and pin steam.exe.
If steam isnt working after this, there's a complicated solution in this link in reddit:

https://www.reddit.com/r/macgaming/comments/1gl55mn/comment/lvt4hu2/

Hope i could help