Noob question.. If I mount a veracrypt vault then it's not secure anymore bc the entire OS can see what's in it. How do I prevent this?

I'm on MacOS and I'm not sure if apple spy's on your files or whatever but whenever I mount a vault anything in the OS can make changes to it and have access to it. It's not secure anymore. What are the best ways to stay secure? I unfortunately can't use Linux so I don't know what to do. Thank you for your help.