Privilege escalation on macOS is very hard indeed. Apple have been improving security for a long time, it is far, far ahead of Linux or Windows in this regard. The default experience in Xcode is that a release-mode app you make will be sandboxed, undebuggable, have protected keychain entries other apps can't read, have a protected file space other apps can't read, and its own code will also be read-only to other apps. So apps can't interfere with each other or escalate to each other's privileges even when running as the same UNIX user. And that's the default, you don't have to do anything to get that level of protection.