https://sneak.berlin/20201112/your-computer-isnt-yours/ by Jeffrey Paul
On modern versions of macOS, you simply can’t power on your computer, launch a text editor or eBook reader, and write or read, without a log of your activity being transmitted and stored.
New versions of MacOS send OCSP requests (unencrypted) every time you open an app or execute a script. It means that anyone (ISP, Governments, ...) can see what you are doing.
It is possible to disable it by modifying your hosts file for MacOS before Big Sur, or using Little Snitch. However, with Big Sur, the OS can simply ignore your rules to block requests and even ignore your VPN (you might still be able to block by doing
echo 127.0.0.1 ocsp.apple.com | sudo tee -a /etc/hosts).
Even worst, with the new M1 architecture it is impossible to install any OS before Big Sur but also impossible to install any OS not cryptographically approved by Apple.
I like the hardware produced by Apple (the M1 Macbooks are extremely fast) but it's hard to like Apple.
Once is happenstance. Twice is coincidence. The third time it’s enemy action.