You do have to give permission to access certain features and folders in System Preferences. This isn't unique to 3rd-party file managers - same for all sorts of utilities like backup apps, screen capture apps, video conferencing apps, etc. E.g. Zoom app you need to grant access to the microphone, camera, etc.
You generally do not need to restart macOS, and there's nothing unusual or nefarious about it. You should trust the app publisher - don't grant apps permissions without being sure the app is trusted.