This begs the question why is it not possible. I monitor the traffic on the computers I own which means I have sometimes to decrypt traffic from applications and then re-encryot before sending from the loopback to the local network I own and then over the wire onto "the internet". I like to know what data applications are sending or trying to send. I like to have control over it. That's not unreasonable in the slightest.
Yet, in the "tech" company model of computer network use, the computer owner is discouraged, e.g., scary browser warnings, SSL errors, connection failures, etc., from placing any trust in themselves. Instead it advocates, if not effectvely mandates, placing trust (and fees, i.e., for "domain names") in some other entity, e.g., Apple, other "Certificate Authorities", etc. The mere act of questioning this model is often attacked by "tech" workers commenting online. Watch it happen in the replies.
Under this model, it is as if the the computer and local network owner does not also own the traffic. Who owns the computer. Who owns the local network. Who own the data. Who should be allowed to view it and control it. If anything, one would think the computer and network owner should be allowed to prevent any third party, including Apple, if they so choose, from initiating remote connections and sending data from the computer owner's computer.
Even after purchase Apple believes it is entitled to collect data from someone else's computer, over someone else's network. And it also believes no computer purchaser ever has an interest in seeing what data is being collected, by monitoring the traffic, let alone an interest in preventing these connections. There is no option provided to globally disable all phoning home to Apple, to indicate "No, thank you."
It was not always like this, folks. I owned older Apple computers that never made such assumptions. The computer belonged to the purchaser. Generally, firewalls were not used to block software pre-installed on the computer by Apple. The so-called "tech industry" has moved the needle and tried to normalise what is IMHO an entirely different scenario.