Ed Bott on Zdnet has written an interesting article about cheap Windows keys and whether Microsoft is interested in stamping out unlicensed use of Volume License and Educational Windows keys
https://www.zdnet.com/article/is-your-windows-license-legal-should-you-even-care/
In the article, Ed explains that a 25-character key purchased from a shady web site is not a license to use Windows, unless you work for the company that bought the original key and Volume License.
The key you buy for $11 will unlock Windows and allow you to customise the Desktop, but it's not "legitimate". A search on Amazon shows an OEM? license for Windows 11 Home costs circa £120 in UK and Windows 11 Pro is nearly £200.
What you have to ask yourself is why does Amazon charge so much and other sites so little? Is Amazon ripping you off, or are the shady web sites selling pirate keys without a genuine license?
Of course when you buy a pre-built desktop PC or a laptop, the cost of Windows is much lower than buying a separate OEM license from Amazon.
It's one of those annoying facts that going legit costs a lot of money if you can't transfer an OEM license from an old machine over to a new build. Anyone got a legitimate OEM Windows 7 license? Try it out with Windows 11. It should work fine.
Most people don't care about licensing details, provided Windows works, plus there are illegal ways to activate Windows that don't involve spending any money at all. If you're going to pirate Windows, why bother spending $11?
Chances are Microsoft will never get around to switching off your pirated key, but it might happen someday. Even if it does happen, it's no big deal. You can go out and buy another "genuine" license for $11 and pretend it's legitimate.
A couple of years ago I took advantage of a magazine special offer and purchased a Windows 10 Professional license for £40. A bargain considering they're now charging £80 for a Windows 11 Pro license in the same mag. It's certainly cheaper than £200 at Amazon.