Snaps have only limited access to your home directory and you can turn it off as a user. They don't have access to hidden folders in your home directory, for ex

Snaps have only limited access to your home directory and you can turn it off as a user. They don't have access to hidden folders in your home directory, for example, so they can't access your ssh keys, config and keychain. Flatpaks are more an "all-or-nothing" approach. Either the app is in a tight sandbox and uses portals to access things like the camera or it has almost complete access to your os. Since portals are a new API which requires app rewrite, most Flatpaks are not sandboxed.