ooops, I already replied to losvedir directly, but for everyone else on macOS I recommend TripMode: https://tripmode.ch/

It's far far simpler than little snitch. It's intended purpose is for managing low-data connections, but I leave it on all the time and use it as per-app network permission manager. The data usage tracking is also nice. By default all new apps lack network access. Takes a little bit of work to manage, and sometimes you get unexpected issues, but it's well worth it. Amazing seeing all the network activity trying to come from apps that really don't need the network at all. Like a terminal... (though for a deeper analysis I'll bust our Charles proxy with TLS interception)