This, to me, is the worst sin of Windows 11. One of the greatest benefits Windows had compared to macOS was that it used to be backward compatible with really old hardware. Real pro move to get rid of that.
Edit: I bought a cheap micro form factor PC that I thought would support Windows 11 natively. Haha, no, the 6 year old CPU on that was not supported.
Think about it. Anything you type into a browser is your intellectual property, you own the copyright to it, unless you're copying someone else's text. In order for Mozilla to pass what you type on to any website you're visiting, they need to "copy" that text (i.e., from the keyboard to the network).
I think this is what they're trying to address with their legalese. It's a pity that it has to come to this, but that's how the legal environment is these days. They can't afford to make expensive mistakes. Perhaps they can keep improving and clarifying the language though.