Wait, Netflix et al use FairPlay in Safari on macOS?

I'm surprised, because Fairplay is publicly crackable.

So is WideVine.

It is?! The only public way to decrypt that which I'm aware of stopped working 15 years ago.

If you still see pirated copies of shows marked with WEB-DL (rather than Webrip), there's a way of decrypting the content directly. I really doubt the methods that are used are public, though.

*Added security for the remote server but massively reduced security for the end users computer.

Any source?

It allows websites to run arbitrary code blobs which interact with a hardware backdoor in your CPU with a higher permission level than the OS. With the multiple exploits that have been found in intel cpus and the Management Engine itself there is no way you should be letting any website do that.